Stuck Set Screw

[mookie21]

I am trying to remove the handle on my single handle Delta shower handle. The set screw is stuck, I’m assuming from the corrosion. I have soaked it in vinegar, have put WD 40 on it. It’s still won’t move. Now I’m sure it’s slightly stripped. The 3/32 hex wrench, doesn’t grab like it did before. Any help or suggestions would be appreciated.

 

[Twowaxhack]

Order a new handle and cartridge. When it arrives, turn the water off and then break the handle off.

Then replace the cartridge and the handle.

 

[TomFOhio]

Also PB Blaster does wanders. If the set screw is striped then its done.