middle collars adjust spring tension/preload

top plate adjusts camber

adjuster knob adjusts rebound/ compression

pretty much under stand everything else

btw. ur coils

And yes...loosen the collar and adujust the hieght you desire. The higher you going the lower the car will be.

but i think your question is in regards to the collar removal

ok so lets say your got whatever preload you want to run on already

and the spring bottom collar is butting up against the collar that holds in the mounting point to the spindle

what you do is you take off the top collar that holds in the mounting point and but up the mounting point directly do the bottom spring collar

doing that you can lower your car whatever the width of the collar was

i would suggest getting coilovers that go as low as you want them to go and still operate within manufacturing specs.