I researched this in depth (as I am sure you did) and came up empty. The main methods used to separate or remove epoxy (industrial strength not K Mart stuff) are chemical/heat related and all out of the range of wood surfaces. If you are replacing the neck because of a neck fault I would pop the board, remove the truss rod and machine route the heel area out of the pocket.
However, before that I would put a wide chisel tip into the neck heel flat section and give it a shock test tap just in case the job was done badly in the first case. There is no benefit in heating and/or cooling the joint prior to this as the temperature point for epoxy separation is the "turn to ashes" range for wood and lacquer.
Yeah, the neck is going away. It's crammed in there in addition to the glue so no pounding or prying. I think a good sized forstner bit and overlapping holes near the edges of the pocket should get me to routing range pretty quick. Like you say, peel the board and get the metal out first. Should be interesting. :) The things people do.
"The main methods used to separate or remove epoxy (industrial strength not K Mart stuff) are chemical/heat related and all out of the range of wood surfaces."
it strikes me that somebody dumb enough to do this might have indeed used the "Kmart stuff". maybe some heat (steam? thin hot knife shoved in there?) might be enough to save the day.
"before that I would put a wide chisel tip into the neck heel flat section and give it a shock test tap just in case the job was done badly in the first case."
before that i would give the perpetrator a good dope-slap and tell him to go guitar shopping.
just how un-fixable is the neck itself? it might actually be more reasonable to go with heat-treating/refretting/whatever it takes to get it playing right as opposed to the ugly task of ripping it out of the pocket.
a variation on the wide chisel is some judicious tapping on the old kitchen knife along the joint in the cutaway.
The neck does not belong to that body as it does not fit!
The epoxy glued Fender neck :
Try to drill tiny holes in the joint, go to a luthier wih steam equipment and steam the joint - most epoxy softens around 100 deg centigrade / 212 F.
If gluing necks it is wise to use hide glue - - it is easier to soften by steam.
What is easier to replace : the neck or the body ? Sure, it is an individual choice, but I guess it requires more skills to make a new neck than making a new body - - - ?? Neck making requires skills !! - and tools !!
The guitar looks more like a Squier than a Fender ?? Fender necks on electrics have never been glued from factory !!
Titebond separates at 212F, Our mulit souce date shows epoxies will not start to lose strength up to 375F, You can boil epoxies joints for an hour and the epoxy will start to lose strength however this is probably not an option here where the substrate need to remain intact, In any instance, this is not a dovetail and there is around 8 square inches of blind glueing surface to contend with (not including the sides of the neck) For info,