How do you change a ignition switch in a 1995 ford thunderbird without having the old keys?

This may sound ridiculous... but force the the ignition switch until the detent "breaks" and you can turn the ignition switch without the key. The risk here is that you could possibly break the assembly that the ignition switch inserts into. If you can get the switch to rotate from the lock position one position clockwise, then you can release the switch from underneath the steering column and pull the switch out.

The alternative is to have a locksmith get the ignition switch to rotate one position clockwise and then you can remove the switch and replace it with a new one from any auto parts store.