I don't know about the Dahon pedal, but the MKS pedal has two metal studs, something like rivets, that you have to remove by pressing them with a nail or something. They came out pretty easily. Once they're out, the whole pedal came apart pretty easily.

My Strida has different pedals, which also have the two metal studs; but these have a pronounced head, which suggests they're more like rivets; so they wouldn't press out so easily (or at all).

So... take a look, and see what you think. I'd suggest you try opening up the pedal, but only after you're quite sure the warranty is already used up and the pedal is not going to last much longer as is.