Tools for Valve Spring Replacement Needed

I made one from an old spark plug, a piece of tubing, and a Nitto air line fitting.
Make sure the piston is down a bit, and tap the side of the Valve Spring Retainer, to help crack it when applying the valve spring compressor tool.
I put oil in the s/plug hole first, then hook up and air hose, and the piston finds it's spot.