On the campus of Rydell High, team spirit is hitting a fever pitch. “We’re all in it together,” enthused “Grease Live” star Julianne Hough during a long day of rehearsing on the Warner Bros. lot in preparation for Fox’s three-hour live musical telecast on Jan. 31.

Hough, Aaron Tveit, Vanessa Hudgens, Carly Rae Jepsen, Keke Palmer and other members of the “Grease Live” cast have been transported back to the 1950s and their teen years for the one-night-only staging of the beloved musical. Stage 26 on the Warners lot in Burbank has been transformed into a high school gymnasium — complete with chatty “kids” hanging out on the bleachers, as if they were skipping class.

“All of us are saying how we feel like we’re back in high school, and it kind of gives us an excuse to be silly little kids and immature and have fun. We’re definitely taking our jobs seriously, but we’re not taking ourselves too seriously,” Hough says.

But there’s no doubt about the incredible amount of work, under the leadership of producer Marc Platt, that has been put in to bring “Grease Live” to the screen. At 9 a.m. with nine days to go until the broadcast, the set is bustling but calm even with hundreds of cast and crew members buzzing around perfecting final touches. Beyond the gym, the 21 set pieces include the hallways of Rydell High to Frenchy’s bedroom to the backlot where vintage cars are parked waiting for Danny Zuko and his T-Birds to hop in. The carnival sequence at the end will also take place outside. (A rain contingency plan is in place, though the L.A. forecast calls for clear skies.)

The sets are so expansive that actors will be zipped around from scene to scene on golf carts in some cases. All of this will be unfolding in full view of about 650 live audience members scattered in bleacher seats at various locales. It’s uncharted territory for TV, but director Thomas Kail, who took on “Grease Live” fresh from his success with Broadway’s “Hamilton,” is taking it all in stride as the countdown to show time begins.

“There’s plenty of things that can happen. I just want to try to prepare for the things that we can control. So much about this is about having backup plans,” Kail said during Variety’s visit to the “Grease Live” set on Jan. 22. Sitting in a booth at the Frosty Palace burger joint, he cracks, “As long as I’m not playing Danny Zuko, I think everything will be fine.”

Speaking of Danny, Tveit walks into Rydell’s gym with an appropriate air of confidence and charm to spare. Dressed in tight black pants (“I love high-waisted jeans,” Tveit says sarcastically) and a tight, white tucked-in tee, he brushes his coifed hair back through his fingers. If he weren’t blonde, you’d think he stepped right out of the 1978 “Grease” movie that starred John Travolta and Olivia Newton-John.

In between practicing routines, Tveit — who starred in Broadway’s production of “Catch Me If You Can” — and his fellow T-birds discuss minor lyric changes, which have been implemented to make the musical family-friendly enough for TV audiences at 7 p.m. on a Sunday night. Specifically, the rocker “Greased Lightning” has had one sexually explicit reference (“p—y wagon”) changed a number of times, and Tveit jokes that he could very well flub on Fox’s live stage. “I’ve had five different lyrics, and who knows what’s going to come out on the 31st,” he says with a laugh.

As Tveit talks, male backup dancers are practicing which direction they should hop over one other on the bleachers for a key moment in the “Summer Nights” number. Across the gym, female dancers are having their slips altered by the 30 costumers on set who intently watch the rehearsal to assess if the garments flow properly with choreography. While conversing with Kail, Kether Donahue is twirling her pigtails and Jepsen is sitting at the lunch table that is filling up with cafeteria food as a PA arranges bright red food trays full of bowls of gummy bears, apples and grilled cheese sandwiches on Wonder Bread (it is the 1950s, after all). But one of the T-Birds jokes that the roast beef sandwich he grabbed turns out to be a prop.

After focusing on the music and choreography at the start, Tveit and his T-Birds co-stars note that the last lap of rehearsals are most challenging as they focus on camera angles, lighting and other elements that will translate the stage favorite to television. “It’s almost like the first day of rehearsals every day,” one trouper declares, standing arm-in-arm with his five buddies. “We’ve been rehearsing it like a play so now to really see it with a whole 360-degree camera experience is exciting,” Tveit adds.

There’s a clear camaraderie among the core ensemble. Jordan Fisher, who plays Doody, wiggles his glasses, cracking up his costars in between routines, and Hough, who stars as Sandy, breaks out into goofy dance moves after she and Tveit finish marking their final “Summer Nights” note under a spotlight. Palmer’s mom (a favorite of the set staff) was observing rehearsal but even with the motherly presence on set, Vanessa Hudgens, who plays Rizzo, adjusted Palmer’s Pink Ladies jacket, making sure her friend’s costume laid just right.

For Hudgens, the chance to be part of “Grease Live” feels like a nice bookend to her big break in Disney Channel’s “High School Musical.” “I did ‘High School Musical‘ ten years ago and introduced musicals to a new generation. It’s a cool thing it’s coming full circle,” Hudgens says.

Although staging a musical for TV cameras is quite a shift from the stage, Kail has been struck by the similarities between the mediums.

“The reality is, rehearsal is rehearsal — you’re in a room with no windows trying to tell a story. There are words on a page and you have to bring that to life,” Kail said. “That’s effectively what my job is — to make sure everyone knows what story we’re telling and how we’re going to tell it, and that job absolutely is the same no matter where you go, no matter the size or the scale of the production.”

Hair, makeup and costumes are a major undertaking for the production, especially as NBC raised the bar with the success of its eye-candy production of “The Wiz Live” last month. On “Grease Live,” the hair department has the tricky job of placing microphones in some of the wigs, including Palmer’s ‘do.

Head costume designer William Ivey Long, a six-time Tony winner, works away in a tiny space surrounded by photos from the “Grease” era — images of Travolta from the movie and Hollywood bad boys including James Dean and Marlon Brando. He’s presided over the design of more than 600 costumes, down to hand-painting scorpion stencils onto leather jackets and hand-sewing curlers onto hair pieces for the Pink Ladies’ sleepover scene. Fun fact: the quickest costume quick-change during the show is 11 seconds for Rizzo, Frenchy and Jan.

“There are other things that are slightly more leisurely — but leisurely means 48 seconds as opposed to 15 seconds,” Kail says. The entire company, he says, is energized by the high-wire act of pulling off such an elaborate production without a net on live TV in front of an audience of millions.

Kail is confident his team will be well-prepped for the curtain call, but the director is still expecting the unexpected.

“I don’t know if I ever feel like, ‘A-ha! We have it!’ I just feel a real sense of pride in the work that this group is doing,” he says. “At 10:01 on Jan. 31, all will be revealed.”