I do all my bindings myself with a paper template found here:
https://www.bindingfreedom.com/paper-tempaltes/
You need a drill, a bit set, a #4 pozi head, and some sort of epoxy or wood glue. I use marine epoxy as I've heard wood glue doesn't seal as well and water can get in. I'd also recommend also having a ratchet so you can get the screws in real tight, and a pair of calipers, or ruler, to double check the measurements of the paper template.
The best part about mounting your own bindings, I think, is the time saved as opposed to the $ saved. In my experience, ski shops usually take about a week to mount skis, so it's nice to get it done in an hour. The worst part is that is it really stressful because if you mess up, it's on you. Good luck.
Also I've heard that you can have a shop drill the holes for you, and you can mount them yourself which is supposed to save $.