Use your fingers and "pry" the back of the pad apart, like you would spread your mouth with your fingers when you were a kid to show disrespect....
that should show the holes where the screws are located.
When you find the holes, choose a screwdriver with as smooth a shank as possible, and additionally, use a bit of Vaseline or other heavy lube on the screwdriver, and the face of the pad, and work a bit down into the holes, otherwise, the screwdriver WILL chew those holes ragged. I've not worked with this particular pad, but be prepared for either flat blade or Phillips head screws in there.
Install with the same care, and you should be rewarded with an installation that has the next guy scratching his head wondering "how in the world did they get that on"........