Yes you have got the battery changing all figured out, it will take you 30 seconds. As far as batteries are concerned, since yours is 5 years old, I think its time to get a new one. Batteries in my car have a nominal lifespan of about 2 years (aggressive bass). I recently purchased an Optima Blue top deep cycle battery and while it wasn't cheap I am impressed with its performance in my car. My sound system sounds better than it has ever done even though this battery is rated lower (amps) than my old one. The benefit of the Optima design is it is closed cell so it is purported to last longer... I can't verify this but it might be something to consider...