Get one of those mini-butane torches from Wal-Mart. I stand a cinder block on end in the door way. I put a 3 foot pipe through the steering resting on the cinder block. Protect the horn wire with a pipe nipple then heat the big nut evenly and you can pop it loose with a 3/8 breaker bar. This whole procedure is every bit of 5-minutes. Good luck..