as far as i knew i thought the PE and PU mounted the same. I understand in wanting to do this yourself. But screwing it up would not be fun. I don't think it would cost much for a gunsmith to drill those holes for you. on top of that dont forget that if you mount a scope you will also need a bent bolt. or it wont clear the scope. You can get these done pretty well for about 60 bucks. or pay a little more and they will send you a new bolt with it already done.
If you do decide to do it and have the tools. please let us know how it went.