how difficult would it be to do this for someone who has never done that before?
I'vre recently obtained some information in regards to what the normal thickness is for the stock hand guards, they usually range from 1/8 to 1/4 of an inch in thickness (yikes!)which is frighteningly thin IMO. There are aftermarket options but they don't follow the same internal specs as the military grade ones (They lack the metal nose pieces, and the retaining pins can wiggle loose after repeated removal)
I imagine if I were to have the hand guards cut in a similar fashion as the above ones, I would have to find a means to first plug the holes that would be created by the the "bipod" cuts in the handguards in the lower halves (Which would be a significant structural weakness), if it were possible to create the horizontal running engravings into the wood without further compromising them, I'd like to do that as well. Provided the internal spacing is great enough and would allow the work of said epoxy and laminating of the stocks, I think strengthening the interior may help improve the durability of the hand guards.