Removing the shaft fitting from a collins PTO

[N4LTA]

I have a 51S Collins PTO and am trying to remove the fitting from the 1/8" shaft. I have a set of Bristol spline and hex wrenches, but it appears someone has stripped the retaining set screw.

Any idea how to remove it?

[K8DI]

Do you need the fitting?

If not, grind/file/cut/Dremel it until you can pry it off…  I’d start with a cutoff wheel across the set screw in hopes to use the slot I cut with a flat blade to loosen it before I have to grind the whole thing away. 

Ed