Hank,
I found it real easy to install. No welding required. I unbolted the OEM system from behind the catalylic convertor. Just two bolts. Mine were not hard to remove since the truck was fairly new. If you have some mileage on yours, you may need to use so penetrating oil. Let the oil sit for a bit and then you should be able to force the bolts to turn.
The Borla comes in several pieces; the muffler/resonator assembly that bolts to the catalylic convertor, uses the oem donut asbestos seal and the two original bolts. The other tail pipe pieces clamp together and there are two new hangers at the back (one for each tailpipe). When sliding the rubber mounting brackets to the hangers and pipe sections, dip the rubber brackets into a mix of water and liquid detergent. This makes them slide on real easy.
I loosely assembled my system on the lawn to get an idea of which part went where before actually mounted it on the truck. There is a pictorial on the instruction sheet that comes with the system to give you an idea of how everything fits together.
Once it's together on the truck, leave the clamps snug but not completely tight so you can adjust the clearance around the spare tire and ensure the tailpipe ends are squarred up properly and pointing the way you want them. They should be straight out both sides with ends pointing ever so slightly down. I found it a bit tricky to get both pipes looking even, but after a couple of tries got it right..
I am very happy with my Borla system and am sure you will be as well. I don't notice any gas mileage improvement but there may a small increase. I do notice that the truck is more reponsive though but that may be my imagination. I use high test gas and I have tried regularr grade but quickly came back to the high test since performance is better with itl Let us all know how you made out. Good luck.
-TM-