I've only replaced old Chevy studs before, using a hammer, so I can't advise on procedure. I would feel safe enough with (4) lug nuts for a limited time - just check them frequently, and no burn-outs!
I drive on salt contaminated roads, and for years I have been applying a thin film of wheel bearing grease to my lug bolts (VW) and studs (all others), and that has always kept them in working order.

My Bentley book says 85 ft-lbs. Looking at the picture, I might try a large c-clamp with a socket large enough to fit over the head of the stud to remove, and another deep enough to clear the stud on the outside to install.