how do you get the brake cylinder to fall back in?

we're doing the rear brakes and i cant get the pads in becuase the piston/cylinder thingy wont go back in.

what can we do?

The rears rotate in, like a screw.

pls. elaborate on this, cuz i think they mean something else??

never mind.. we went down to the bmw dealer and they let us barrow this tool we needed..

thanks any ways!
mel

Joker, Electron Mike has it right. The pistons in the rear calipers need to be rotated as they're pushed back it. It's got to do with the park brake mechanism.

that's kool!

just didnt know if the person advised understood the reply!!