As I’ve done a million of these mods, I can tell you what you basically need to know:
That’s the holy grail of SE painting. You only need one color, pick whatever color you like, spray, watch it finish and then let it sit around for a day.
To cover up your turbo hole, put your art over it. Be it printed vinyl adhesived down, laminate adhesive, lamilabel (suggest avoiding, notoriously shitty) or something high calibre like mamemarquees level stuff.
Completely disassemble your case, including removing the top plate and old art.
Wash your case off with soap and water, hit it with a tiny bit of acetone (like nail polish remover) if you’re especially anal like I am.
Then let it fully dry, and take your spray can and do light coats until the entire thing is covered. lightly wetsand with 600 grit after it dries, then spray again until you get a nice smooth texture.
put the metal plate back on and put your art down, covering up the hole in the plate where the panel is.