Fitting is easy - run the power from the battery, run the earth to a nut/bolt in the boot, then run the RCA leads and remote down the other side of the car.
Pop the headunit out, plug the RCA's into the headunit and wire the remote lead to the blue & white wire.
then its just a case of running the sub in for a little while, then start tuning it to get the bass you want out of it!