Late winter or early spring you can remove misplaced or damaged etc branches.
The do come back from old wood, but i've only cut them back into the brown wood that is about 5mm-1cm that still had the odd leaf on it. I am not sure how they do if cut back into really old wood. It depend also whether you want fruits or not. They flower late spring time and the fruits start falling autumn time. Dont prune after flowering or else you will not get any fruits