On the pot, two of the lugs shouldn't change when you rotate, those will be the input and the ground (hooked up essentially in the same manner as the stock pot.
On the 4-lug pots I have seen, there will be one lug between these two, and that will be equivalent to the center lug on the original pot, then the other lug will be the loudness tap.
If the two lugs that don't change are the two outermost lugs, then you'll have to do some measuring and comparing to determine which is correct.
In any case, the risks are exceptionally minimal here with this tweaking.
