I did it by myself without spring compressors. I used 4-5 zip ties on the stock springs to hold them down when undoing the top hats, which surprisingly worked. The aftermarket springs are soft enough to where you can compress the completed assembly with one arm and start to thread in the top nut with the other. You WILL need an impact or passthrough socket like
this to remove and install the top hat nut though. The nut sits in a recessed well in the top hat where a typical wrench cant get to, You need a socket with a pass through for an allen key to undo the top hat, or an impact gun to zip it on off. The install took me about 90 minutes and I was taking my sweet time. When you do the rears make sure you undo the 15mm bolt from both the left and right side so that the while beam comes down. The first time I attempted it I only dropped one side at a time and I had a HELL of a time trying to jam the springs in with my brute strength alone.