I did it in bits and pieces. I started with items I thought nobody would notice. I'd add a new item every couple weeks. It turns out people did notice, they just didn't say anything.
So my progression was neutral sneakers, hoodie, jewelry, flat colored straight legged jeans, hair style, curvy boot cut jeans, solid colored t-shirts, makeup and nails, full time, coats, sneakers with bright pink highlights. I still get nervous around certain locations and people. I haven't fallen back to male mode in 3 months now, but I do sometimes fall back to those neutral jeans/sneakers depending on where I'm headed.
Each additional step you take makes it easier until you get to a point where you're just sick and tired of changing to walk out the door and stop doing it.