[V8] Pushing in rear brake cylinders

[gbmarc at cox.net]

Is there a secret trick to pushing in the rear brake cylinders, prior to fitting new pads?
Normally I just put a big 'G' clamp on there and push 'em in, but the manual says they need to be rotated too.
I'm finding it very hard to push and rotate simultaneously.
I think I need secret tool VW999xyz.
Why didn't they just put a big slot in the end so a whacking great screwdriver would work?!!!

Mark.