It takes a lot for Margot Robbie to transform into infamous figure skater Tonya Harding

It takes a lot for Margot Robbie to transform into infamous figure skater Tonya Harding.

The actress, 27, put on her ice skates for the role that’s earning her the best praise of her career — and three nominations already at the Golden Globe, Screen Actor’s Guild and Producer’s Guild Awards. It took 5 months of intense training for Robbie to skate similar to Harding on the ice — and a couple boxes of cheap hair dye to look like her, too.

“To me, the hair and the aesthetic, the way she put on makeup — it told the story beautifully,” Robbie tells PEOPLE in the latest issue. “It was about embodying the life of someone who grew up the way she did.”

She adds of the process, “Our makeup artist only used makeup that she bought really cheap from a strip mall, only makeup that Tonya could have worn. And the hair was dyed with only cheap hair dye, and she permed it time and time again. For me it wasn’t about replicating the looks, it was embodying the spirit of Tonya.”

Credit: Neon; Focus on Sport/Getty

Aside from the impeccable recreation of some of Harding’s most iconic looks, Robbie also worked hard to emulate the skater’s biggest moments on the ice. The actress already had natural talent on skates from her ice hockey days, but learning how to get on her “outside edges” proved to be trickier and she put in months of work to get it right.

“She started skating 3 or 4 times a week for five months and she was incredibly diligent about it,” director Craig Gillespe tells PEOPLE. “The amount of stuff that she could do was amazing. For that end sequence when she comes out on the ice, those 30 or 40 seconds with all those turns and spins, that’s all Margot. She managed to be in it so much more than I expected.”

Margot Robbie in I, Tonya
| Credit: Everett

Robbie was so diligent about the role that she even worked on having different pitches to her voice when playing Harding at various ages. It made her performance eerily realistic.

“She’s no fuss, no ego,” says screenwriter Steve Rogers. “There were days when Margot had to play Tonya at four different ages. Her physicality is so much like Tonya’s, it’s miraculous.”

I, Tonya is in theaters now. The 2018 Golden Globes are set to air Sunday, January 7, on NBC at 8 p.m. ET/5 p.m. PST.