wtrdog,
I just did this two weeks ago on my '77 cb550. Go get 4 hose clamps (1 for each Piston) that will be used to compress the rings. Start with the two center pistons (2,3) all the way up. Make sure the rings are offset like they call out for in the manuals. Cover the rings with the hose clamps and tighten down, tight but not too tight. Then place the head over the two middle pistons and start easing it down, You will probably have to tap with a rubber mallet or something around the head as it will be a little tough going. Once the rings are inside the head, simply remove the hose clamps from the two inner pistons. Continue tapping head down until you just make contact with the two outer pistons. Then crank the crankshaft to start the two outer pistons into the head. Start tapping down with rubber mallet. Crank the crankshaft more and keep tapping until the rings are inside the jugs. When far enough, unscrew hose clamps (these will be a little harder as there will not be much room to get them out, but it can be done), and tap jugs all the way down.
Once you start moving jugs down over pistons don't raise again. If you do you may have a ring pop free and will have to reset again, or run the risk of breaking a ring.
Have a buddy, wife, kid, dog or whoever you can to help out. Plus it helps to have someone there to cuss at and blame besides yourself.
Let me know if I can help with anything else, this is all still pretty fresh in my mind.