Everyone else pretty much summed it up...take em to a shop. Jig is necessary! Bit size is dependent on ski not binding. If there is no metal in the ski...then you typically use 3.5 x 9.0/9.5 If there is metal in the ski....then you typically use 4.1 x 9.0/9.5This is very general as well. bit depth is largely dependent upon mounting position as well as ski and screw length. A 40$ mount is a lot cheaper than new skis!