Just put new lifters in my '80 westie. found it very easy to take the
retaining spring our, remove the top piston and pour oil into the
cavity. Had to hold down the bottom plunger and put a nail through one
of the holes to keep it in place. Put the top plunger back on, and the
snap ring. pulled out the nail and perfect. NONE of them knocked when
the engine started.

dan