Insert the left end of the replacement top oil ring rail into the oil ring groove directly above the oil ring expander.

The top oil ring rail, bottom oil ring rail, and oil ring expander all share the same oil ring groove. The top oil ring rail will be sitting directly on top of the oil ring expander.

Continue inserting the top oil ring rail into the groove by working your way around the piston clockwise.

Make sure the top oil ring rail is completely inserted into the groove.

Repeat this step for the bottom oil ring rail.