Ok so fitting my additional side lights didn't go well. I added them by cutting the side light wire then butting the cables together with the new wires.

Took the side light out and made it all up. Tested it with power and worked fine, put it all together and tested again and I've now a light down. Either something came loose or the led died.

My question for now is is there a way to remove crimps without just cutting them off?