This picture ^^^ makes it look like it is actually all one piece of plastic. If it is, you'll need to cut them hinges off unless it has a cover or something you can take off to neatly take the hinge pins out and release the door.
Instead of just any old saw, I'd suggest a dremel type tool to do a good job.
Also look into taking the door apart, as you might be able to remove everything apart from two small pieces that attach it to the hinges.
Good luck mate, come back with result pictures