On ours there are screws at the bottom of the "handle" that sticks up. The entire top part comes off. So you essentially have two pieces - the top handle part and the base with the belt. This is how they come in the box. There may be caps or covers over the screws so they aren't obvious.
Do you still have the manual that came with it? Maybe you can find one online. Ours shows how to put it together so you could just work backwards to take it apart.
Good luck! Those babies are heavy! lol
Ours is in the basement and I dread the day we have to move it.