To answer the original question, the most difficult part of the installation is finding the two alignment lines and arrows under the glass at each mounting point. First, you install small PPF pads at each location. Then you slide the mounting hooks forward from the rear of the roof glass to get it under the rubber water seal, then you'll feel it engage a metal cleat under the arrow in the glass. Do this X4, mount the racks, tighten down firmly but by hand until they snug down to the roof, then lock and put the caps on.
Removal is the reverse and takes a fraction of the time. One drawback is the SECOND time you want to install them. Unless you left the PPF pieces on the car you will not have them anymore. You'll have to try to find them again (good luck with that!) or make new ones yourself as I did. Otherwise a good rack. It does whistle a bit but I'm sure it's far better than more conventional racks