There is a $20 kit with plastic templates and a couple of different hole saws to use on a drill. Pin in place, mark, cut/dremel/chisel/drill/whatever out. Pin the other in place, marks center point for drilling handle hole. Other side does lock works hole. Works great. Even an id10t like me can do it (I've replaced every inner door in our house at least once, and several of them 3x... I have destructive kids). Part I have trouble with besides the precise placement is cutting the bottom/top to fit, always end up screwing something up, and the lowes folks won't do it for me even with exact measurement and a promise of no-take-backs ....
I end up using/needing to use - circular saw (trim top/bottom to fit height wise w/ carpet, etc), hand planer (fix width, usually less than 1/4"), chisel(s) and hand drill to cut/saw from template, and template kit.
