Rear brake caliper prob....Help

[rbull51]

I tried to wind the piston back into the calpier but the rubber seal around the edge is getting twisted up as i do it. Is there any way of stopping this?

[tcb 180]

You have to free it off the groove it sits in on the piston and ensure that you turn the seal in time with the turning of the piston but in opposite ways if you see what I mean?