Defocussing with the black dot is say step 1, generally yes, you would like to have it nice and centre for both sides of focus. I would remove the 3 locking screws as they serve no pupose. Only leave the 3 x collimation screws.
For the beginnner:
http://www.schlatter.org/Dad/Astronomy/collimate.htm
Advanced:
http://legault.club.fr/collim.html
Without tracking it can be harder, but as higher magnification as you can. I have a 5mm vixen and then i slightly defocus and try and have nice concentric rings.
Hey it takes many nights to get the hang of it. ie if i turn one of the collimations screw, what actually happens, am i making it better or worse??
It just takes practice