I have just received my new EZ-leveler II.
Forgive my ignorance but I simply can't figure how to use it.

Where does it get fixed exactly??
I believe the bottom plate screws into my tripod head, but how on earth is the upper plate fixed to the NN (I have NN5)?
Is it possible to install it between the tripod and the tripod head?? (I have a GITZO GT1530 and a G2771M head).

Also I can't figure out either the use of those little nobs which are supposed to set the detent interval. Although on the top plate of the leveler is written Rotator D3L, nothing rotates!
I think I must be missing something here

Note that a simple user manual would be very useful when supplying this small but not that obvious piece of equipment.

Please help.

Many thanks