Michelle Trachtenberg

Former "Buffy the Vampire Slayer" star MICHELLE TRACHTENBERG trades in her stakes for skates in the new, inspirational drama from Disney, ’Ice Princess.’ Tonight on ET, we’re on the set with Michelle and her "Sex and the City" co-star KIM CATTRALL!

In this ugly-ducking-transforms-into-swan story, 18-year-old Michelle plays Casey, a brainy student on the fast track to Harvard under the tutelage of her strong-willed mother (played by JOAN CUSACK). But Casey dreams of being a championship skater, and when she gets the opportunity to train under her best friend Gen’s (HAYDEN PANETTIERRE) mom, played by Kim Cattrall, she puts her Harvard plans in jeopardy.

With the sole support of Gen’s hunky teenage brother, Zamboni driver Teddy Harwood (TREVOR BLUMAS), Casey takes on the challenge of her life in the ultra-competitive championship circuit — and must fight to make it to the top and follow her dreams!

"Her entire journey throughout the script is all about her passion, all about her desire to be the best," says Michelle. "The true definition of ’Ice Princess’ to me is just following a dream to be great at whatever you want to do."

Michelle had to train hard to look like a pro on the ice. Once an average skater for fun, now she can land "toe loops," "waltz jumps," "spirals" and "spread eagles."

"It was initially scary," Michelle tells ET. "I started training back in January, but now there’s just a confidence there. There’s nothing like getting on the ice and going really, really fast. It’s a lot of hard work. I’ve had many bruises. No one can say I haven’t suffered for my art."

Perhaps scarier for Michelle, though, are the teensy weensy skater outfits she has to wear for ’Ice Princess,’ including a wild, retro-’70s getup. "I thought I was getting off easy," says the 18-year-old actress. "I did my bikini scene in ’Eurotrip’ and I thought I was done. I’m like, ’Great, I get to be all covered up now.’ Nooooo — skating skirts are, like, up and flippy! I’ve been working out really hard, though."

Watch ET for more of Michelle and Kim on the set of ’Ice Princess’!