With the strut out, remove the rubber grommet to expose the top hat nut.
Install the spring compressor and tighten the spring until it’s almost loose.
Use an impact gun to zap the top nut off and then you can remove the top hat and OEM spring.
Thankfully the front lowering spring is much shorter then the OEM one but you’ll still need to compress it.
With the top hat back in place, a special deep open ended socket is recommended to tighten the nut since you can slide an allen key in to hold the strut shaft and tighten the bolt.
We used an impact gun and were VERY careful when tightening it. It’s very easy to strip the threads if you’re wreckless so take a lot of caution with the impact gun.
If you had a lot of resistance removing the strut from the hub, using a scotch pad to clean the hub and strut surfaces.
Slide the strut back in and repeat the process by pushing down on the brake caliper and sliding the strut back into the fender well.
Tighten the top three nuts in place.