I did this on my beat up 450DX one day. *It's a crap guitar (since I've gotten a hold of it) so I wasnt careful about precision. *This shows clearly the areas that need to be "cleared away" to be able to put in a Lo Pro in place of the TRS you may already have, and dont like.

Yes the work is sloppy, this doesnt reflect my other workmanship I've done.