What type of tool is needed to adjust the screws for the Bike Yoke Revive clamp? I rode on my BY Revive for the first time since having it installed and realized that the saddle needed to be tilted down a bit. But the adjustment screws under the clamp don't appear to accept an allen wrench. It looks like the adjustment screws may accept a Phillips head screwdriver but I tried a random small Phillips screwdriver that I had laying around and it didn't seem to connect in the screw insert. So what tool do I need exactly in order to adjust the BY Revive clamp screws?