Its easy to install these. You can use a plug so you can easily unplug it when you want the doors off. I'd install it only on the drivers door though. The way to do it is you use 2 relays.
Using my image to explain it. the green wires coming from the top are the 2 wires coming out of your alarm unit. When you press lock, 12 volts is sent to one wire and the other one is ground. When you press unlock, 12 volt is sent to the other wire and the 1st one is ground. If you're not pressing any buttons they are both ground so there is no voltage = no lock, no unlock. The red coming from the top represents 12 volts straight out of the battery (fused obviously). Next the black wires are ground. At last the brown are the relays. You use 2 relays. The way the door actuator works is you have 2 wires. When you apply voltage to one and ground to the other, it either opens or closes. If you reverse the wires it does the opposite thats how it locks and unlocks the doors. With this said you need a ground and a 12 volt signal to lock it and then the opposite to unlock it. Thats exactly what the alarm is sending you however most of the alarms are not strong enough to use without aftermarket relays and thats why you need to do it this way.
Relays. the coils side acts like a temporary electric magnet. If you apply the voltage to it, it creates the magnetic field and pulls the flapper arm and connects it to the other end. (red X) If there is no voltage (no magnetic field), its stays on the other end (black X) At last another wire is connected to the base of the flapper arm.
So the green wires control the voltage (magnetic field) at the coils, a very low voltage is needed so no damage occurs to the alarm. When voltage is given from the alarm it creates the magnetic field and the flapper arm moves.
The purple wires go to the actuator (picture bellow). When no buttons are pressed both replays have their flapper arms in the down position or ground. When one is pressed the magnetic field activates and pulls the flapper up and then that gets connected to the 12 volt so it sends the 12 volt signal to the actuator while the other relay still says at ground.
On a side note, the actuators use regular electric motors. think back when you were a kid. You wire a motor one way, it spins one way, you flip the wires it spins the other way. Thats the same thing happening here.
Here is my image to explain it.