Screwing in the rear brake caliper piston..88 80Q

[MXHOWES at aol.com]

I'm installing some new rear pads on my '88 80Q. The Bently shows  using a 
socket head wrench and screwing in the piston to compress it. My piston  does 
not have a such a socket, it does have two slots in the outer circumference  for 
maybe some sort of a key.  Does this sound correct? If so, I will make  up a 
key and push & turn it in.
 
Thanks in advance,
 
Jim
 
'88 80Q
'85 4KQ