safe to drive to the shop but i wouldnt make a habit of driving with broken wheel studs.

a couple more steps on a 4wd but not a major

very easy to replace.
remove wheel
remove brake caliper (tie it up out of the way so its not hanging on the hose) (2 bolts only from memory)
Turn manual hub to free wheel position and remove the hub cover (6 bolts)
remove the snap ring from the end of the drive axle, then remove the bolts of the hub (another 6)
the hub assembly should pull straight off

remove the bolts holding the disc and hub to remove the disk
press out the old stud
press in a new one