Are these for function or more for looks? Install will depend a lot on what you want from the rear skins. Like Jaimie said there are many ways to mount rear glass. If they are for looks only, then I would rec just installing them directly over your stock sheet metal. This way you don't have to worry about waterproofing or anything. If your needing more room to accomodate more up travel and clearance, then be prepared for a lot of fabrication.
At minimum you will need:
sawsall
grinder +cutoff wheels
dremel tool
welder
dzus fasteners or fender washers
new wheel tubs if you are worried about water damage
longer gas hose and replacement/relocation of gas door
Also keep in mind that no matter which company you go with for rear glass (fiberwerx, Perry's, Maniak, or any others ) remember that it will not fit perfectly. Minor (major in some instances) trimming and sanding of the glass will be neccesary. Especially the inner lip around the wheel area, and the rear most portion of the quarter-panel near the tail lights will need work.
All this being said, if your a fairly decent mechanic, have some welding and body work skills then it is not a difficult job.
The hardest part is making sure all the tabs are properly aligned before welding them down. If your off at all, your glass will not line up and look like a$$. I suggest drilling holes in your glass first, then have a buddy hold it in place on the truck while you make the marks for the tabs on the sheet metal.
Dzus tabs or a decent fender washer kit is what I rec for mounting, but get the security heads so no one runs off with your skins. Camburg sells a really nice fender washer kit...It is much easier to install then dzus tabs, and it looks awesome once on.
hear is a link to get you started :
clicky here page 3,4, of this thread talks about mounting rear skins on an explo and shows you pics of how to cut your stock sheet metal.
PM me if you have any other questions.
EDIT: LINK will work...
www.desertrides.com site is down for the moment