Sorry I was not more clear, but as Spec says the two-wire loom that comes with the new light fixture ends with bare wires.
I think the best way go about this is to do as suggested, solder and heat shrink it, then run it through the loom.
Since the loom, between lamp and connector, runs inside the interior and exterior rear hatch body panels, now I just need to think through the logistics of how to remove the old wires while pulling the new ones through the rear hatch. Guess I clip original wires near the original lamp, attach ends of the new wires to the original wires , then pull original and new wires through the rear hatch panels and toward inside of the rear hatch, till they pop out of the hole.
Am I thinking right here?