Wiring cadillac tail lights to 83 s-10

Need someone to explane what wires go where for my caddy tails (89-93). My truck is an 83 S10. I wanna ask cause I wanna do it right the first time and not get it all soldered in then come to find out I did it wrong. Also how do you shave bumper? Weld mounting bolts in then grind off head???

i just cut the reverse wire on mine since caddy has no reverse lense and plugged them in only diffrence is caddy has a push in bulb and your truck has twist in
other then that its same plug
mine was a 93 by the way

So what wires go where?