As you're looking at the face of the studs, tighten clockwise. However, be very careful as the pinion can easily strip if the threaded cap on the end of the wheel cylinder is rusted and stuck. Use an open end wrench, not a box end or ratchet, and if it doesn't turn easily, don't push your luck. You'll have to pull the drums and free up the caps by tapping with a light punch and hammer. I've found that lightly lubricating the threads on the wheel cylinder adjusting caps is a good idea.
