That is how my headaches started. After buying the car I took it to a brake guy and I wanted to change the studs at the same time. He took out one on the front and ruined the hole (and the hub) -
You have to cut off the swage. Rusty claims you can use a 5/8 hole saw You can buy cutters for them.
Are you planning on upgrading the brakes? Either to larger drums or disk? Id say if you don't need special nuts for your wheels, and might go to bigger or disk brakes, leave them until you need to bother with them
When / if you go to a tire store RAISE HELL. Make it CLEAR that you expect the mechanic to PAY ATTENTION, and that if they ruin any studs THEY will pay for them.
