Hijacker 5th wheel hitch

Got a good deal on an Hijacker Ultra Slide w/rails, hitch was used twice, I paid $200 bucks. I called a local RV place in town and they told me I needed a $650 mounting kit to put this hitch in the truck. That was just the mounting kit, labour not included. How the hell do these things attach to the vehicle? Are they mounted to the box with reinforcements, or do they attach directly to the frame?

Loaded 5th wheel is sitting ~15k, so I'm not real keen on just bolting it to the box. However, I'm also not super keen on dropping another $1k to get it installed. Is it really rocket science or can it be done in my driveway? Are there really special "mounting kits" necessary?

Apologies in advance, I hate noob questions, but I want it done safely.

It bolts through the box to the frame. You could have someone that knows fifth wheel hitches to fab up the frame support brackets, but you would want to be careful that they actually know what they are doing. Also research the correct kit for your truck on the web, it may be a lot cheaper.

Can't help you on the Hijacker.
BUT on my Pullrite slider, I installed the frame rails myself. There are seven bolts per side. The holes are already in the Truck frame, IF you get the correct frame rail kit for the truck. Further, I took my rails off the old truck and moved them to the new truck, cause they are like $600 for the rails. I did buy new bolts when I transfer them to the new truck. It's was a afternoon job for me.

I've got a high jacker slider in my obs if you have the rails it should be some grade 8
1/2" hardware and some heavy duty angle brackets drilling holes and bolting in the driveway if you do not have the rails redneck trailer supply got my last set for like 200$
I'll be by my truck in a little bit and snap some pics and post them up

Bed rails

This model is 10 years old

Bolting is advised however in 10 years and 140k no problems yet