This tool will install spiral-style lock rings in the proper manner.
I use the butt-end of a deep socket to get the spiral keeper ring centered, and down farther inside the sleeve. A small amount of oil smeared on the inside of the sleeve will help the spiral slide a bit better.
Insert the sleeve into the piston:
(you can see my spiral keeper pushed down in there)
Next, Insert the Driver Piston and use your palm to press the spiral all the way - The sleeve is tapered down, so the spiral with wind up and pop into the wrist pin groove.
I usually insert a spiral keeper in each piston first. Then heat the piston a bit, this helps the wrist pin slip right through with ease . . . Don't forget to lube the wrist pin bushing.
I install the piston with "indented dot on top" (or if it doesn't have the dot)
with small "fin" on the inside wrist pin boss . . . .
TOWARDS THE PINION / CAM-SIDE of the motor.
Install Pin, and Piston - Repeat Procedure.
Using a small, flat blade screwdriver, press down around the top of each keeper, and make sure it's down in the groove. Since I can't see as good anymore, I take a lighted magnifier and make sure my keeper is fully seated. This tool works slick - I've installed hundreds of spiral keepers over the years. They stay in better than snap rings if installed correctly.