Here is some more detail on the method just using your fingers. Once you have the piston and rings installed on the engine case, slide the cylinder on to the piston until the bottom of the cylinder is touching the first ring. Make sure it is making contact all the way around. Use your thumb and index finger to compress the first ring. I like to start with my index at 12 o'clock and thumb at 6 o'clock with the notch on the ring at 9 o'clock. Press the ring with your fingernails while gently and evenly pushing on the cylinder. You may only get part of the ring to slide in, that is OK. Slowly and patiently keep going around the ring until you get it all to slide in. I found that if it does not go in all around, I go to the opposite side from where it is in and try to push that section in. remember to try and push on both sides all the time as you did when you started otherwise you may just be chasing the section that does not slide in around the piston. Be patient, once you figure it out you will find it easier. Make sure to keep the cylinder bottom parallel to the ring. If you don't it will not work. Once you get the first ring in, push the cylinder down until the bottom is touching the second ring, again, make sure the bottom is parallel with the second ring and touching all the way around. Now repeat the fun you had with the first ring. I you get bound up, gently pull up on the cylinder to get all of the second ring out and start over. I have pulled the cylinder up in frustration and managed to get the first ring out also at this stage. that can be very frustrating. Go slow, don't get frustrated. The ring will compress easier near the split. Remember gentle and even pressure to keep everything parallel. It does get a lot easier once you figure it out.