Scud.. you can do it either way. If you want to install the cylinder over the piston, you can slowly work it down by pushing each ring together with your fingers, or use a ring compressor like this.
The trick with these is to lube everything up well, tighten the compressor just enough to make the rings flush with the piston, and give the cylinder a good smack with your rubber hammer. The idea is for all of the rigs to go into the cylinder with that one swat. Being hesitant about it will (probably) leave the oil ring still out of the cylinder.
The old rule used to be if the rings came out of the cylinder, to glaze break it and install new rings. Not so much any more. I wouldn't bother at that low mileage..