How do you remove an ignition cylinder?

I have a 1998 Toyota Corolla CE, I had to buy a new ignition lock cylinder because the tumblers were busted inside the original 1 & it wouldn't turn the key all the way..it wasn't the key cus I had an original key cut at Toyota...anyway Ive removed all the steering column covering but I can't get the faulty lock cylinder out because the key won't turn to acc so I can push the pin & take it out...what can I do if I cant turn my key to acc to remove the lock cylinder?