Interior and Upholstery She lost keys & she's determined to do it herself

Here's some information on on a possible DIY solution.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/

But IMO one of your bigger problems is how to get the old lock cylinder out. It will be necessary to break the bar holding the lock cylinder in place. After breaking the bar and removing the cylinder then it will be necessary to repair the damage.

I had a situation occur with a new to me 2003 GT where the key suddenly stop working. I called a locksmith out. The locksmith had everything needed to repair and re-key the lock cylinder after breaking the bar to get the old cylinder out.

Note, It's very EASY to remove a lock cylinder when you have a working key. That why your problem is a steeper climb with no working keys.

I believe you can go to the original dealer and and they can make you a new key