I just took my 2A apart and ran into the same situation. A small pry bar loosened the stock and it came right off. I guess the grease acts as an adhesive.
The guy in the video does suggest tapping with a punch made from wood and a hammer. If you do not work with this stuff you may be flummoxed by the process.
I was a little disappointed he did not bring more formality to the process. It would have been nice to see him use at least a cheap
rifle vise or sandbags or something.
Backyard shadetree gunsmithing has been the death or injury of many a fine weapon.