cv joint & calliper

[mike]

having discovered that the split & loose abs ring on the rear of my B5 S4 is part of the cv joint rather than a separate item a new joint has been sourced, anyone got any pointers as to how it comes off & goes back onto the driveshaft?

along similar lines, whilst doing a disc and pad change I discovered the calliper piston won't rotate more than about 10 degrees, it not seized as such because it still grips the disc when the brakes are applied but it won't push/screw back so new pads can be fitted. It has free movement for the 10 degrees but then goes solid,  I tried applying some force with the rewind tool and it broke the tool. I'm guessing some sort of internal unrepairable derangement but open to suggestions.