I removed mine when I painted.
I simply removed the brake line where it enters the rear of the caliper, and then popped the end of the hose in a freezer food storage bag and then taped it around the hose to catch the leaking fluid.
I then found a bolt with the same thread to screw into the back of the calipers to prevent fluid leaking out whilst the paint was being done.
I gave mine a total of 15 coats:-
1) remove the calipers
2) cleaned the gunk off with brake cleaner
3) used a dremel and a wire brush end to clean in the hard to reach areas
4) used brake cleaner again to remove any residue
5) made some cardboard masks for the inside of the caliper and wrapped thin strips of masking tape around the bleed bolts (after removing the rubber caps from the bolts first).
6) I then bolted the calipers to a plank of wood to make handling painting easier.
6) gave them 4 thin coats of red oxide primer
7) gave them 5 coats of red gloss then left them to dry overnight
8) gave them 6 coats of lacquer and left top dry for the day
9) applied the decals
10) reattached the rubber caps and fitted the calipers to the car
11) Used an easibleed system to bleed them - right rear, left rear, front right, front left
12) Nice cup of tea and stand back and admire the work!
