Well, I'm pleased to say the nut change was very easy and has solved my problem with a dead B and E string played open. Grabbed an old wooden ruler and one light tap of the hammer and the old one came right off. The core nut, which my PRS friend The Fight sent me, was pretty much a perfect fit. I put a couple of drops of medium viscosity cyanoacrylate (that's super glue!) in the slot and stuck the core nut in there. Set the guitar aside and let it sit overnight, then strung it up this morning. I could definetly tell the difference, and mainly the open B and open E are now sounding great.