Need help! Blazer tank kit on 72 Chevy C10

[nomad0231]

I leave for Afghanistan in two weeks and need help FAST!

I bought a gas tank relocate kit online and after some research have found its actually for a Blazer, but they sent it saying it fits the trucks. I can't figure out how to mount it tho. I removed the cross bar where the spare went, and tried playing with the tank, but can't seem to get it. It's a plastic-ish tank.

Also looking for a rough estimate on how much it will cost to have cab corners, floor pans, and paint job. Fixing to take it to the shop so itll be ready when I get back!