Wouldn't I have to get a new spindle or press a new lug

 

Not the spindle; you'd either be pressing a new stud onto the hub, or replacing the hub/bearing assembly.

 

What UT said.I think that every option for getting the lock nut off has been suggested.Something has to be sacrificed now if those methods don't work.It's a new stud or hub assembly after that.

 

FWIW, replacing the hub/bearing assembly is super easy. Pretty sure it's gotta come off anyway to deal with the stud, and at that point it may be easier to just replace the entire thing. Did one on somebody else's Mustang before, think it was about $40 or $50 at Autozone for a new hub.

 

It sucks living in an apartment. Not enough tools:/