Cobie Smulders Opens Up About Transforming into Ann Coulter for ''Impeachment: American Crime Story' '

Cobie Smulders did extensive research when she said yes to taking on the role of Ann Coulter.

In an exclusive interview with PEOPLE, the How I Met Your Mother alum, 39, opens up about playing the conservative commentator in FX's Impeachment: American Crime Story, which premiered Tuesday, and the work she put in to capture every essence of Coulter.

"I did not consult with her," says Smulders, 39, who took over the role from Betty Gilpin after the GLOW star was forced to drop out due to scheduling conflicts. "I listened to almost every one of her books. She's written quite a few and I've listened to a majority of them, if not all. So that was helpful."

"She's a very public figure and she has a certain way of speaking in cadence and personality," she adds. "So I looked into that. Also, this is a depiction of pop culture in the nineties. It was hard to gauge where she was at mentally and where she was, what her drive was at that point in her career. I did a lot of research!"

The new series will cover the affair between former White House intern Monica Lewinsky (Beanie Feldstein) and former president Bill Clinton (Clive Owen) that ultimately led to his impeachment.

Sarah Paulson — who previously appeared in The People v. O. J. Simpson: American Crime Story — stars in the series as Linda Tripp, the former U.S. civil servant whose secret tape recordings of her conversations with Lewinsky helped expose the affair. The Impeachment cast is rounded out by Annaleigh Ashford, Edie Falco, Margo Martindale, Billy Eichner and Colin Hanks.

On top of channeling the mental and emotional aspects of her character, Smulders enjoyed the physical changes that helped transform her into Coulter, 59.

"One thing I will say about Ann, she's got fantastic hair," says Smulders.

"There was a big process with the wig. The makeup department did a great job shading and altering my face to be a little bit more similar to hers," she explains.

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And while they didn't share any scenes together, Smulders enjoyed the physical changes her husband and costar Taran Killam (who plays civil servant Paula Jones' husband, Steve) underwent as well.

"Taran went through different versions of haircuts," says Smulders. "They weren't great or super attractive, but you know, he can pull off anything. It was nice to have a little change."

As far as sharing a project together, Smulders says it was "cool" for both personal and professional reasons.

"Taran was hired on the show first, so I had been hearing about the production and how great it was," Smulders shares. "He was just really positive about the experience."

"It was truly nice for us because our family's here in Los Angeles and we were both able to be here and work in the city that we were also homeschooling our children," she adds. "It was fun."

Written by Sarah Burgess, Impeachment will primarily be told from the perspectives of Lewinsky, Tripp and Jones, whose sexual harassment lawsuit against Clinton led to the exposure of his affair with Lewinsky.

Lewinsky, 48, serves as a producer on the show, which is based on Jeffrey Toobin's book A Vast Conspiracy: The Real Story of the Sex Scandal That Nearly Brought Down a President.

Impeachment: American Crime Story airs Tuesdays (10 p.m. ET) on FX.