04 ford mustang car won't start after replacing stealing column

Have you reset the inertia shutoff switch?

That's the button in trunk.. yes we did.

First step. Stop making the situation worse by working on it yourself. Get a competent mechanic that knows security systems to work on it.

Did you by chance get the door lock as well? Roll windows up (if possible) lock and unlock driver door with key. Then turn to on position, wait 10-15 minutes until anti theft lite stops flashing, key off, wait a minute or two, then try starting. Might also try holding the key in the door in turned position of unlock for 30 seconds