Okay, here's the deal. This has been covered many times in the Parts/Accessories section. So do a search over there for "backup lights" and you'll find all the info you could ever want. Here's a link to one thread that should be helpful:
-
Backup Light Mod -
A couple of thoughts though. First, you need a relay. I've posted on this many times and the reasoning is simple. The switch in the tranny is only meant to carry the 26W/2Amps the stock lights use. When you add another 110W to the circuit for an additonal 9Amps (11Amps total), it will eventually blow that switch and that will cost you a couple hundred bucks to get fixed. A $5 relay is pretty cheap insurance to do it right in the first place.
As far as putting them up high or down low, it's up to you. Personally, I put mine down low. I didn't want to try and run wires up to my rack when I put them in. Second, like Brent (OffroadX) said, the hatch is in the way if you want to use them as a work lights. Which only brings up another issue that you may/may not be concerned with. In most states (Michigan I'm positive on), white lights on the back CAN ONLY come on when actually in REVERSE. That is, legally, you CANNOT have them wired to a switch so you can turn them on at will. Sure you can have a switch in place so you don't have to use them, but in most states, they can only come on when actually in reverse.
Okay, the legalese is over. There's advantages to both up high and down low. The choice is up to you and how you intend to use them.
Hope this helps!
-G-