To do the color change a majority of the panels need to come off.
http://members.cisdi.com/~anesthes/sanding/
Now depending on the color, this could require the car to be painted twice.
You might want to have the jams, and unexposed surfaces hit, then put the car together and hit it again. (thats what we're doing with mine). The reason is the color match. Some colors just don't match, even with the same mix same gun sprayed the same day.
I'm also in the process of a 91-96 bumper conversion (have all the parts, started mock up last night), and after mounting the rear bumper I may even just paint the rear section of the car together. Not sure yet. The rear bumper requires a lot of stretching and pulling to get it lined up right, and I'm not sure I want to do that with a painted bumper (regardless of the flex additive).
The doors don't really have to come off the car. You can mask the interior off to hit the jams, and the front jams can be done with the fenders off (which need to come off.
From what I can tell, the front bumper HAS to come off. You just can't paint all of it with it bolted to the car. You'll miss spots, or have uneven spots.
So I guess what I'm saying is. It's a trade off. If you don't pull it apart, you will miss some spots, see some factory color in places, or worse spray over dirt you didn't blow out.
However IF you take it apart, you risk having a color mismatch and having to wetsand and respray the whole thing a second coat.
FYI, I have about 10 hours of 'take apart' time into everything, and about 80 hours of sanding. So lets say 90 hours at avg body shop rate of $38/hr is $3420 just to get me this far. The body shop will prime/seal the car, and block the whole thing and spray it for about $1800, then I will flat bed it back to my shop and spend an estimated 12+ hours putting it back together (without scratching anything). So say $456 at body shop rate. So assuming I didn't do any of the work thats about $5676 right??
Any body guys wanna chime in?
-- Joe