Originally Posted by mech
Man, learn something every day. I don't recall noticing a scarf joint that far into the neck but as well as this one could be hidden by using the same stick, there's no wonder. I do see the mismatch in the grain on the side now. Looks like about a 7 degree cut which would have removed about 5/16" of wood at the base of the cut (just eye-balling).
The finger board will need to be un-glued from the peg head portion for a good clean up.
What brand is it?
Open the joint enough to work. Using thin scrapers, clean the joint. A scraper can be made from a thin pallette knife, an old X-acto saw blade or the like by turning a hook on the end. It is important to stay away from the edges of the joint. Any wood that is removed is going to be easy to see and feel. It is also more work to fix another problem.
Another way to do it is to heat the blade till it is good and warm and place it on the mating surface. It will melt the glue and stick to the metal. Pull it, clean it, do it again until both sides of the joint are clean.
Do not use sandpaper for this task!
Once the joint is clean, apply woodworking glue, clamp, clean and do any touch up work that is necessary.
Fingerboard removal is unnecessary. Removal is more of a hindrance than an advantage, and it turns this into a much more expensive job.
This is a job for the seriously handy only. If you hear the word "tool" you think "software", that a vise is a bad habit, or that stuffing toothpicks in a stripped out strap button hole is woodworking, take this to a pro.