“This one will be a hard thing to describe,” Zellweger said about donning a short brown wig and dramatic makeup for the role. “It was a great life blessing. It really was.”
The film is set in 1968 at a time when Garland headed to London in an effort to revive her career.
She died at the age of 47 due to an accidental overdose and her drug and alcohol issues are covered in the movie.
Zellweger -- who sang songs like, “Somewhere Over the Rainbow,” live during filming -- said she ultimately wanted to show all facets of Garland’s life, including the good, the bad and the ugly.
“She mattered so much to so many people and she touched the lives of so many people, we want to show her the love that she shared with all of us,” she said. “And, boy, what a special experience that was.”
Garland’s three children are also represented in the film, and her real-life daughter, Liza Minnelli, admitted to ET in June that she was wary of how Zellweger would portray her mom.
“I think she's a wonderful actress and I just hope they don't do what they always do,” she said."That's all I've got to say."