It's pretty straight forward.
There are three screws around each of the coin chutes that hold that angled piece to the door. Unscrew each of the six screws and the thing should pretty much just fall out of the door. Make note of the lengths of the screws as there are a couple specific locations certain ones go into.
From there, the coin reject "buttons" should also just fall out.
The face of those buttons are held in by a simple interference-fit set of "pins" that are part of the face of the reject buttons.
The way to remove that face is by the two longitudinal slots that are on the sides of the button. Insert a screwdriver in there and GENTLY twist it in each side slot to pop the face off.
Once the face is off, you'll see the recess that those inserts sit in and then you can remove them and replace them with whatever you like!
Then, reverse this process to reinstall!
I've installed these on mine and they look pretty nice. If I remember to take a picture tonight, I'll post it up here tomorrow.