I also put together my rear coilovers. Not sure anyone cares, but i could not find a step-by-step anywhere online so....
Everything laid out.
Lower ring threaded on and also lower plastic washer.
You have to remove the Adjustment knob to install the upper ring.
Slide the coil on followed by the top washer.
Install the top ring, then install the snap ring onto the top of the shock. This locks the top ring into place.
Tighten the lower ring until its snug and reinstall the adjustment knob. Not that hard. But took me a minute since I dont play with Coilovers everyday.
The lower ring has a screw for a Lock-down once tightened and ride height set.
Also kinda cool, I did not realize these are Fox Shocks. I thought Fox was its own brand.