The London school of Furniture used to do a guitar building course with Stephen Delft. I did a one week intensive guitar repair techniques course there many years ago.
I do all the set up of my guitars myself, but I always send refrets and neck repairs to an experienced luthier.
Having had an idiot once break a truss rod in a glued in neck guitar (after telling him that the truss rod wasn't going to fix the problem - how can tightening a truss rod cure a back bow?!), I now make sure that I know the guys who are looking at it. THe only good thing from this was he recommended a really good luthier who fixed it (Will Scott in Pembrookshire).
It may seem expensive for a good set up with an experienced guy, but a new neck is a lot more!
