I had a CREEE light that the cord went bad inside the light. I tried to disassemble, but it was sealed, glued together, and very difficult to access the inside. Perhaps more work later.

I've found that plugs are a pain to work with. I think the "Factory" ones are hot molded at the factory and built essentially in a single unit (thus well sealed). If it was me, I'd cut the wires, solder and heat shrink tape the middle.