What do I do to fix leak at hot water valve?

Hi Hank...

Exactly where is it leaking from the valve? Is it leaking at the packing nut (see image) just behind the handle? If so, you should just need to tighten the packing nut a 1/4 turn and that should stop the leak. Hold the valve with one pair of pliers and tighten the packing nut using another pair of pliers... do not over tighten.

If the leak is elsewhere please let us know, OK?

Mark