ok so when I bought the car, I noticed that on the rear springs it has some part wedged between coils and would like to know what its for and if and how do i take it off..

 

That raises and stiffens the spring some, maybe he put on lowering springs then decided that it was too low.

To take it off, take the load off the spring by having the wheel off the ground, then put a socket extension in the square hole and twist the part 90 degrees.

 

ok cool, i actually want to lower it, so does it matter which way i twist? also, would it be hard to put it back if taken off?