the talking celestias, I'm working on a tutorial for it as well :3 they're actually pretty easy to take apart with the right tools, you don't need an xacto to get the head off, you just need to heat it up, I used a blow drier.
As far as getting the body apart, it is held together with screws. You'll see little plugs of plastic in several places on one side of the body, you'll need to drill those plugs out to find the screws, and then unscrew it. It will take a little force after that but it will pop apart, and then you'll have access to the tail and all the electronic pieces, and will be able to get at the wings at that point.