Flipping the front upper strut mount gives the front suspension approximately 1" more droop at the expense of 1" up travel. It allows for better suspension action with coil spring spacers or taller coil springs. Instead of flipping the mount, you could also make your own upper strut mount spacer to lower it in relation to the strut tower. Whatever you prefer.
While you have the upper strut nut(and large indexed washer) removed, the frame supported by a jackstand and the a-arm supported by a jack, remove the three nuts holding the strut mount to the strut tower. These can be reached through the engine compartment.
Remove the mount from the vehicle.
Using a large socket and a hammer, drive the three studs out of the mount. You can also drill them out if you prefer.
Now Per side you need 3 bolts, 1.5" long and 7mm threading(or whatever size SAE you have that fits), grade 8 or stainless preferred. You also need a stack of washers or three 3/8" thick round spacers.
Now you bolt the strut mount back in place, upside down with the washers or the spacers between the mount and the tower. The washers or spacers are to keep the mount's curved edge from crushing flat as you tighten the bolts.
From bottom up the order is: bolt, washer, strut mount(pointing down), stack of washers or spacer, strut tower, washer, nut. You can add another nut to lock it in place or even use lock washers under the nuts. Tighten securely.
Jack up the a-arm far enough to slide the strut shaft through the mount, replace the large indexed washer and nut. Tighten securely. That's it.
