I assume that most legs work the same: there is an outer part that mounts solidly to the trailer, there is an inner leg that moves up and down with the motor driven screw, and the innermost leg that can be moved up and down manually and is held in place by pins.
If there is a small hole in the outer mount, and the innermost leg is lowered out of the way, that will expose the screw to any lube shot through the hole in the outer mount. The hole should be fairly high so as to hit the screw and not the inner leg.
I hope that's clear, kind of hard without a diagram. When I mounted the Bulldog legs I totally disassembled them and greased everything and put it back together.