im pretty sure that if there dc's it wont be paint but anno....
however if they have been over painted, then you need to strip the brakes down completely till you are left with the two arms....then hit em with nitromors or equivalent paint stripper to remove the paint, thrnif there is annodising underneath, to strip that you will need to get that off using caustic, (available from b and q ) or i use high strength oven cleaner, which is caustic but i feel its less harsh and more controlable.
i think the hard man that is scary leary did a how too on stripping anno, and the geezer didnt even use gloves, he truly is double hard.
hope this helps.
Dave