Hello. There is no special mechanism needed, it's simply a pyraminx with added pieces. There are a couple of ways to do it.
1. The easiest is take the corners off of several pyraminxes until you have enough to glue or fuse to the pyraminx that will serve as the base for your stellated pyraminx. As the pyraminx stickers are faily thick, usually restickering is not a problem. The corners are usually glued with a bit of glue to a top piece and will usually pop off with a small screwdriver and a bit of force.
2. Of course if you have the means, you can make a mold from the corner piece and cast your own custom pieces.
3. To take apart the pyraminx, pop the corners off and this will expose the screw. Unscrew all of the screws and it will readily come apart. When putting it back together, though, take care to place the screw straight in to the interior ball as misalignment is easy to do and will result in a hard to turn puzzle. (I did this when making my octaminx and like to never discovered what was the matter)
4. Incidentally, the stellated pyraminx is no harder to solve than the normal pyraminx, but it does look cool.
5. Now that we have a Master pyraminx, I'm waiting for the first stellated Master pyraminx and Master bandaged pyraminx!