...I've always done it by hand, and never broken any rings. The key is to take u'r time and don't rush. You can start with either 2/3 or 1/4 pistons in the highest postion. You can put the tranny in gear if you want to stop the pistons from moving. Spread a couple rags across the bottom of the pistions so you don't drop anything in the case. Now ease the jugs down til you make contact with that 1st ring. Now just take u'r finger nail and squeeze the ring until it starts to make its way into the cylinder. Do this with both pistons. I like to keep an old kitchen knife handy to press the rings up into the cylinder. Now when both those top rings in compressed and just in the edge of the cylinders, with even pressure, give the top of the cylinders a nice bump down with both hands. Easy now! Not to much, thats how u break rings. If it works like its supposed to the cylinder will now be down to the 2nd set of rings. Keep repeating this process until the cylinders are completely on those 1st 2 pistons, then repeat the process for the 2nd set of pistions. I've gotten frustracted, and sometimes you need to walk away, but its usually a relatively easy job, you just gotta take u'r time. Good luck...
...also helps to oil the cylinders up good to reduce the friction as the pistons slide on...
