Abstract: Tooling and process for installing a split type, circular snap ring into a slotted or grooved wrist pin journal of a piston utilizing an installation sleeve member with an internal bore therethrough which is positioned against the piston so that its bore is aligned with the piston's wrist pin journal. The bore in the installation sleeve including a tapered passage to progressively radially inwardly constrict the snap ring as it moves axially through the installation sleeve. An elongated plunger assembly is moved axially to engage the snap ring and move it through the bore of the installation sleeve. The plunger assembly is sized to permit it to move through the entire extent of the tapered portion and into the piston's journal so that in turn the snap ring is moved into the wrist pin journal and finally into alignment with a retainer slot or groove into which the snap ring can radially expand outwardly into a seated position.