Suspension Question Regarding Bilstein Adjustable 5100 - how are these adjustable?

I just ordered my Toytec suspension kit with the Bilstein 5100s.
Basically, 2 shocks with 2 adjustable struts (5100 Bilsteins)
I have never dealt with coilovers.
I have only installed basic Bilstein shocks without ever trying to level out a vehicle.
My question is that based upon a quick visual I don't see how the front struts are "adjustable". I know I a spring compressor to remove old struts from coils. Just don't get the adjustable part of the shocks.

I am sure this is a ridiculous question...

 

There should be three groves that the bottom spring holder thing will go to. You choose which one you want.

 

i just got mine in the mail today. Mine have four grooves and a large "c" clip that fits in one of the grooves. You simply pry it a little to get it out of one groove and pick the groove you want based on how much lift you want. Then the bottom plate (which is the metal silver plate that hold up the bottom of the spring) slides down and catches on the overhanging c clip, then you just put coils on and good to go!

 

Good evening,
Figured I would throw my 2 cents in on this one...
Also the Gen "1" Bilstein 5100 Fronts will have the "3" snap ring grooves..
The Gen "2" will have the "4" and the reason they are "Adjustable" is for the reason that a few of you had stated.What you are doing is adding pre-load to the spring in order to change the ride height..That is why when you set it at the 2.5" Mark, they are pain to get the springs on because you have to pre-load them so much.
The main advantage to the 5100's is they have been valved to help compensate for the added Pre-Load...
Hope this helps....
Thank you,
Sonny