On the rear, the idea is you can fit different spacers to control how much drop you want.
You have a 5mm and a 10mm spacer, or you can do the same as me and fit no spacer on the rear. Gives a good drop. You just need to fit one of the plastic bushes at the bottom of the spring so you've not got metal on metal contact.
Fine adjustment can be done by using the threaded section, which I didn't touch, but was needed for corner weighting