how do I remove/replace studs on 7 1/4

If you don't say anything about the left hand threads to the alignment shop,, they'll likely break them off, and have to replace them.. no charge..

They are sooo unusual, most don't realize the L threads exist..

On many customers vehicles,, I've placed a laminated,, Big Red Label, with - "STOP,, Left Hand Threads" inside the hubcaps, and a dab of red paint on the lugs...