Just done all around my movano (master realy) and i had the same problem. I ended up using mole grips to wind the pistons back in and they were tight.
As for your hand brake remove the cable and keep moving it back and forth. If you do get it free the torx bolt that holds the arm on has a spline fitting so you can adjust it there aswell but make sure the piston is moving in and out as you move the leaver before you use this to set the hand brake up.
Good luck and let us know how you get on.
Just read your comment PLEASE PLEASE don't use any oil/WD40 on the cables as this will let any dirt that you flick up stick and get draged into the cable sleeve and start grinding away at the protective coat. May sound daft but they are dry when you buy them :loser:. Hope this helps