How do I remove the gear selector (shifter arm). I'm removing it to install my raask rear sets which come with different linkage and shifter arm. I've removed the nut on the set screw bolt but can't get the bolt out to I assume relieve it from the shaft. It's a super awkward position and no room to hammer it out with like a tap. Thinking if I drill it out it will come but want to know if that's my answer before I take the drill to it. And yes, I've heated it up and tried to hammer a wedge between the arm and case to no avail.

Any help is appreciated