What you have to do is open the Fusion and remove everything that is inside. Its not as hard as it sounds because everything electical is on little modules that are held on with screws. The hardest thing for me was just getting the dang case open. I damaged it a little because I stripped one of the screws on the side. It doesnt really hurt it but if I was going to sell its kinda annoying. Just look at things and determine what you have to do to remove them. Once you get everything out it is very simple to paint the case, as it requires no taping off. The plastic sides should come off too, but be careful becase it is a plastic that damages easy under stress. Just be careful with the electronics and remember where wires go, I had to disconnect 3 or 4 to get things out. The power supply is a little tricky but I cant remember if I had to take it out or if I just did. Have someone help you lift or slide out the keybed, I think that you would want to be careful not to flex it.
I used regular Gloss Red paint with a thin white primer. I put a little Clear Coat on it. Then when I put the thing back together the plastic is still the original color so it looks factory. I would only recommend doing this if you are confident that you wont break it. It makes a big mess with all the parts so have a clean area.
One question that I have is; Which way does the Power switch go to turn the Fusion on? Up or down? I think that I may have put it back in backwards so it is opposite than it used to be.

It still works it just seems that I have to switch it the wrong way to turn it on than I did before.