The sides of the neck joint fit snuggly (often times with shims) in this psuedo precise dovetail-ish joint; however, the holding power comes mostly from adhesives, as can be seen by the next photo.

All that yellow stuff around the neck block is the glue. Usually, an epoxy of some kind. It takes quite a bit of heat to remove the neck, but because the neck joint's imprecise fit, it is not that hard to get the neck off. Lots of time and patience required, but I've never had to resort to steaming (in the traditional sense anyway). There are some threads that deal with neck removal in the OFC/BFLG forum (including this CC247), and so I'd take a look there for more details.

About the Truss Rod. Since you're gonna be removing the neck from the bowl anyway, you might want to wait on purchasing a new truss rod. You can cut a straight groove in a stripped female hex nut and convert it, so that a minus head screw driver turns it. If it doesn't work, Stewmac sells replacement truss rods for reasonable prices.

The above neck for my CC247 was cleaned up and converted to a bolt-on neck.

The conversion enabled me to correct the guitar's neck/bridge alignment, intonation, and secured the neck joint for good. If the neck ever needs to come off again for whatever reason, the removal will be a cinch. The guitar feels much more solid, and while it's no USA Ovation, it certainly is one of the best sounding/playing Celebritys around here. Hope this helps! Good luck with your project, and keep us posted as to your progress!