Buy some 0 gauge cables and an inline circuit breaker. Hook one end of the cables to the inverter and the other end to the batteries. The circuit breaker should go in the battery box, just cut the red wire about a foot from the terminal and put it there. They're difficult to find, so just go to a high end stereo installation shop and get it there.
get some overkill fat cables so they don't get hot and start a fire. Get a fuse so it will blow out instead of starting a fire. American Wire Gauge Chart and AWG Electrical Current Load Limits table with ampacities, wire sizes, skin depth frequencies and wire breaking strength
Inverter Battery Cables | Inverters R Us This place sells cables for inverter... Then watch video on YouTube... Its not difficult.
Dude you had to ask in another thread how to remove the lights in the back of the cab and how to pull the radio out of the dash. Isnt that a clue that wiring, even simple wiring, might be above your skillset? Seriously dude, think about this. Please. While i might feel you have no business owning a truck and are only going to help drive rates down, i dont want to see you burnt alive while your sleeping either.
I'm seriously thinking no one who posted understands why the op needs to get a professional to install any inverter. Let me ask this to those who think anyone can install one.... where do you fuse the inverter and why?