Hi Chris, it's as simple as pulling back the top slide as if you were cocking it, but then hold it there don't release it, (Saftey on, no mag or Co2 in) now turn the pistol over and look inside the slide you will see a couple of screws, loosen these and the sights can be moved from left to right. Don't loosen the screws off too much you want the sights to move using a little effort no flop all over the place, or you will lose you zero when you turn it over again to tighten them up.
Hope this helps
Jason