You need to swap out the heater box with an AC heater box (with evaporator installed inside), install a condenser in front of the radiator, install the compressor, install an accumulator, and install all the lines/hoses to connect all that together. You need to swap out the controls on the dash for one with AC. Then you need to deal with wiring. I don't know how much is already pre-wired for AC. You truck may already have the appropriate connectors and wiring or not. You'll also need to do some simple wiring under the hood for the pressure switches and compressor clutch. And finally, you'll need to add oil to the system, evacuate, and charge with refrigerant.
Adding AC to a truck is a project I would undertake. The only parts I don't have experience with are the wiring, and swapping out the controls and heater box. Everything else I've done before and it was pretty easy.
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