I have done this a few times. You could use the same holes, but if you have a drill, it isn't that hard to line up the holes if you take apart part of the binding, then mark the holes with a sharpie. Drill it with a very small drill bit. It would also help to put a little wood glue or something similar as well. Just mount them 1 or 2 cm back from their usual point. I had a binding pop off (shop mounted) right before a rail jam, I went to the shop and they basically did what I just told you in 10 min and the binding is still on, they are my rock / shitty day set up now, but the binding is still on.
Like I said, I have done this a few times, and the times I didn't redrill, they came out after 4 or 5 days of riding, but they were warped in the first place so it took some trial and error to firgure out the glue and drilling. I also work at a shop, but not in the tuning department. They do pretty much what I just said, but there is a clamp they use to line up the bindings, and a machine to test them which is pretty much worthless because most people crank the dins as soon as they get on the hill. Let me know if you have any questions, I hope it works. Shops are getting out of hand with mounting fees, mine charges 75 now if you didn't buy it at the shop.
