Pulled pork cooking time
Pork leg (fresh ham) is quite amenable to the low and slow techniques used to make pulled pork, such as braising, slow roasting, or barbecuing, just like pork shoulder (butt).

The final product may have a slightly different texture, as the ham is a little leaner than the shoulder.

Questions of cooking time are very difficult to answer, as they depend on the specific temperature, shape of the cut being cooked, method, and the individual characteristics of the individual cut.   You are looking for an outcome, which is that the connective collagen is fully gelatinized.  This means holding at internal temperatures of around 180 F for some time.  You will know that it is done when it pulls apart easily with a fork.  Fortunately, low and slow techniques tend to be very forgiving, and while possible, it is difficult to overcook using them.

I would recommend checking the fresh ham about the same time you would check a pork butt of the same thickness in your recipe or technique.  Pulled pork also holds and reheats exceptionally well.