I would also suggest buying the "Rear Subframe Locking Bolts" ...Whiteline makes them (I have a pair but Im putting them back on my car). They are about $30 and worth every penny. They lock down the rear of the car, so it doesn't move side to side as much. I loved that mod. Cheap and significant.
Install is just a matter of screwing them in (you will need an airgun tho...so go to a mechanic's).