I installed rear air bag suspension helpers into Mitsubishi Pajero without removing the springs. This is a polyair kit, but it's basically the same for airbag man and other kits.

Air bags help to level out suspension in your 4x4, particularly when you are carrying heavy loads like car fridges, engels, drawers, aftermarket rear bars etc. And are particularly useful when towing camper trailers, caravans, boats and other heavy loads.

These air bags sit inside the coil spring and assist the spring with the load weight.

If unsure, always get professional help, but this is a job that you can do at home in your garage with basic tools. Install time, about 1-2 hours not rushing.

Helpful tips:

Use spray lube when slipping the top and bottom rubbers and the air bags through the side of the springs

Always inflate the air bags to near-maximum pressure when the vehicle is unladen / not loaded. Then add the load. Then let the pressure DOWN to the correct ride height.

Locate the schrader valves / air inflation valves and air lines in a safe location, away from obstacles that might damage the system when off road. Remember, mud, dirt, sand etc can block the valves from working when you need them. Put caps on the valves, and wrap them in tape to help prevent contaminants entering the valves. Also, avoid running air lines near your exhaust.

Install an exhaust heat shield (included in most kits) to stop heat from the exhaust melting the airbag or air lines.