Hi, Scorch,
Not all pads were put on with Philips screws; the older ones are attached with round-head slot heads. Since Blackcote is removing the old pad, he probably doesn't care about its appearance, but for installing the new one, I agree on using a round screwdriver, but recommend using liquid hand soap as a lubricant rather than oil as oil will rot some types of rubber. A little cake soap is also good on wood screws for a lubricant that won't harm wood.
Almost forgot. With a new pad there are no holes in the rubber. You have to make them by inserting an awl through the holes from the front, then insert the screw in those holes. If the holes don't line up with the old ones, use a pencil or a ball pen refill to mark the stock and then pre-drill the holes.
Also, once the pad is installed, you trim it down by using masking tape on the stock and then using a belt sander (you can do it with a sanding block or file, just takes longer) to trim off the excess pad. It takes a lot of care to not mar the stock.
Also, be sure to follow the stock line. Nothing shows an amateur job more than a recoil pad that has its bottom (toe) cut to line up with the barrel rather than with the original stock line.
Jim