Here is a great tip for replacing a door knob and striker plate, mainly the striker plate. You know how when you put the new striker plate up and the screw holes just don't line up or off just a hair. Use this 1/4 cent part, tooth picks. Yep that's right tooth picks, round preferably. Just brake/cut in half and fill in hole and tap in snug with end of screw driver or hammer, brake off flush or use a utility knife to cut off flush, replace new striker plate and screw in screws. Now when the screw starts to bite and grab the wood the tooth picks tighten up and gives the screw the resistants it needs to start a new hole and that allows the screw to drive in straight and not at an angle back into the old hole. Just thought I share this as I just had to do this myself. This same technique works for the cylinder lock as well. Works great! And here I thought I retired from the finish carpentry industry.