Again, it twists back but you might find it earier to loosen the resevoir cap first which can be found n/s tucked away near the bulkhead. Try using adjustable pliers or mole grips to grip the piston. Remember to refasten the resevior cap when you finish.
Mac
May 2010
you need to wind the pistons in usually anti-clockwise
stu morris
May 2007
You need to turn the piston anti clockwise as well as pushing it due to the internal threaded rod which is part of the parking brake assembly. There is a specific tool but large pliers do the trick.
gareth
April 2007
I can answer this question...
peugeot 807 rear brake , how do you push back the piston?