B7 rear brake tool?

[Henry A Harper III]

Haudi,

I've ordered some rear discs and pads for my 2005.5 A4q avant (2.0T manual)
after politely refusing the dealer's offer to replace them for $400+. Never
mind that I'm a little skeptical of the "need" for new discs because "they
are too thin and can't be turned after going through a set of pads" - not a
big fan of turning rotors in the first place. Ok, they are ordered anyway.
There is a small lip on the rear discs indicating some surface wear so not
completely bogus. Didn't need to replace rear pads on my GTI or 200q in 15
years or so...this car only has 70k on it, must be some good rear brake
bias!

Not having seen the pad-free calipers yet, and wishing to avoid a delay of
car-less-ness while it's up on stands: what sort of tool will I need to turn
the rear cylinders back in when replacing pads? Is it a square drive of some
sort, pin spanner, Torx?

I don't have a service manual for this car yet because it's been over a year
that I've had it and the only thing I've had to do is take apart the hatch
to figure out why the squirter wasn't working (something jammed in the
nozzle), and replace some DRL bulbs. I even let the dealer do the oil
changes (2 now, with courtesy inspection to protect my vehicular
investment).

Thanks,
Henry Harper