I got a great tip from Wolfgang Herter at Columbia Car and Cycle 'the' Laverda guru in North America - when rebuilding old Brembo calipers and trying to remove the rusted bleeders, place a 8mm box end wrench over the nipple, apply very slight pull using just one finger and tap away on the top of the nipple with a hammer, it may take many blows (it took several minutes on some) and the nipple will break free and turn out very easily. Minimal pull is the key and use a brass hammer, the bleeder nipple will end up being destroyed, a good reason to replace the bleeder with ' Speed Bleeders'.
I just did two very ugly calipers, the pistons, pins, springs and pads are rusted junk but the caliper bodies will turn out great.
