Are you sure there aren't screws that are hidden somewhere? Sometimes things are designed so you can't take them apart unless you have a manual that tells what to do. Or so you don't hurt yourself and sue the company. Plastic parts sometimes are snapped together and held in place by screws. My paper shredder had a label stuck over one of the screws; removing the label voids the warranty. I had to take it apart as I found plastic envelopes jam the cutters. Who cares? Cheaper to trash it and buy a new one if it won't work or go together.
Life is like water-skiing; if you slow down, you go down.