You can now install the supplied A/C belt; make sure all the pulleys line up. | 
Reinstall the cooling fan and shroud, and then reinstall the alternator belt. The cooling fan is important for the kit to function correctly. If it doesn't pull enough air through the condenser and radiator, the A/C won't get cold and the engine will get hot. | 
Now we can focus on the interior. The first thing you'll need to do is remove the glovebox door and liner. |
Once you have the glovebox ripped apart, take the screws out of the heater controls and give it a good rip; it'll come out. Then remove the screws, unhook the cable and wires from the heater box, and gently remove the controls. | 
Now you need to change the fan switch. This gives you a three-speed blower and is a simple swap. | 
The new switch is connected to the supplied harness, which connects to the new heat/air-conditioning box. |
Speaking of the heat/air-conditioning box, you will have to drill two holes in the firewall for hoses. These are for the new heater-hose connections, as the A/C connection comes through the original heater-hose holes. Using the supplied template makes it easy. | 
Now just slide the heat/air-conditioning unit under the dash; make sure the piping connections go through the firewall holes. It's best to have a friend help you with this. | 
While one of you holds the box in place, the other can fasten it using the factory stud holes and the proper fasteners. There are a couple brackets that also help support the box from inside the car. |