It's very simple, but most of the time the simple things are the most helpful.
I always used the big 10 pin jack for programming my AVRs because my programmer also had the 10pin jack.
With the time lapse module for the rollei camera a new requirement came up: Space. I wanted to make it as small as possible, so I changed from 10pin to a 6 pin jack.
This is how to make a working connection between a 10pin and a 6pin jack.
You need one of each jack (6pin and 10pin) and a 6-wire flat cable.
Step 1: Pin assignment
Take a look at the pin assignments of the first pictures and the colors of the flat cable in the second picture.
That gives us:
Step 2: Prepare the flat cable
Then make a clean cut between the individual wires for about 4cm on one end of the cable. Make sure not to cut into the isolation of the wires!