Been asked to swap pads n discs on step daughters passat.

Assume pretty std vw stuff, pistons wind back in ? Any tips ?

Yes wind in calipers you can remove the discs without removing the caliper brackets ...

I think the Audi I helped my friend to do had the left hand thread on one side, do VW have the same ?

Done them this evening, both clockwise found it easier to whip caliper off and wind them back held in vice.