IL / Suzo Happ Coin Door Reject Button Replacement

[The Plainswalker]

Hello all.  I recently purchased a 4-player coin door from Arcade Renovations (this one: https://www.arcaderenovations.com/suzo-happ-four-entry-arcade-coin-door-with-coin-mechs.html ).  I also purchased red reject buttons to replace the yellow ones it comes with.  I think I see how to take everything apart to replace the buttons (and their yellow housings), but after hours of searching, I haven't found any instructions or videos on how to actually do this.  So, couple of questions.  Does anyone know of any kind of instructions I can follow so I don't end up wrecking this thing? 

Also, does anyone know where I may be able to find a purple reject button for this coin door?  I am working on a TMNT kind of theme and would like to eventually replace the buttons with colors matching each player color.  Blue, red, and orange are easy to find; but purple doesn't seem to exist that I can see.

This is my first post here.  Apologies if I have overlooked answers to these questions.  I swear I tried to find the answers before posting.  =)

Thank you in advance.