By the way: I recommend leaving the center part of the low friction pads in place. I've had mine disassembled three (!) times now because of the failing scroll wheel click - and the original pads are still OK (with no additional glue added)...

PS: Annoying the Logitech designers did not leave the screws immediately accessible - especially when they messed up in production (the plastic part on the motor - hopefully the cyanoacrylate means I'm done opening it for that!)

I also ended up with a loose spring... I'm pretty sure it goes here: Spring-placement... (Skylar, you are welcome to include the picture!)

Cheers!

When you are "in there" anyways, you might consider gluing the the plastic thing on the motor axle with cyanoacrylat. This part working it self up is the typical cause of the wheel click function dying! ;-)