Actually quite simple if you have a little mechanical skill (pvc pipe connections). It utilizes a three way valve off your filter outlet piping, so you can direct all or part of the total water flow through the solar panels. The water from the panels goes back into the line that goes back into the pool.
You can mount the panels on your roof or you can just mount them on a frame that rests on the ground. The number of panels you need is based on the gallons of water in your pool. I have 4 panels for my pool. You can buy these direct from Sunheater, Leslies, or just about any large scale pool supplier. They have all of the hardware you need to mount them. Mine are about 15 years old and look like new.
IMPORTANT - you must drain them completely in the winter if you live in a cold climate. Drain, then blow them out with air. I learned the hard way the first year I had them. I didn't blow them out and the little bit of water left in them froze over the winter. Since the tubes are just plastic, I had about a thousand leaks when I turned the water on. Vegas would have been jealous of the fountain I had.