I would like to convert the headlights on my 87 S-10 Blazer to H.I.D. or just bulb but i have a couple of questions

1. I know where i can get the housing for the bulb conversion and it will fit my blazer, but do i have to rewire the whole lighting or just clip the wires in the front and reattach to a bulb unit.

2. Can i take the housing off of a newer 1st genertaoin housing such as a 94 blazer and put it in mine?

any help will be appreciated and thanks