If I do not have a key How do you remove an ignition switch on a 1966 Mustang?

Undo the chrome ring at the front of the ignition, the ignition switch assembly can then be removed from the back of the dash. Unplug the lead in the back remove the ignition switch & throw it in the bin. You could try drilling the barrel out, it would probably be best to buy a complete new assembly, you wont get the old barrel out without a key. You will also need new door locks.