My normal series of cotter removal...
- Cotter Press (Got the current one from BikeSmith Designs)
- Hammer and punch
- Heat with a torch then try the press
- Heat with torch then try the BFH
- Drill it out from the blunt end
I have been pretty fortunate that I can usually get it out by step 3, I can only recall one in recent years that had to be drilled out. I have never "ridden" one out. Rode one old 3 speed with a sheared off cotter for several years and it never came loose.
Aaron