There are a series of videos you may find useful.
Ritchey-Chretien Collimation: Step 1 of 3
http://www.youtube.com/watch?v=2EC5N5bfB9A
Ritchey-Chretien Collimation: Step 3 of 3
http://www.youtube.com/watch?v=RUOza5EHRNg
Ritchey-Chretien Collimation: Step 3 of 3
http://www.youtube.com/watch?v=25vR-MbCf0M
The videos use the Circular holographic attachment, but the squares should be similar in theory.
Terry