Please remember that I am not an expert. I am a computer user with a hoby of fixing and upgrading old computers. Please notifiy me if you find any errors in my guide or if you would like tohave something added.
It is not required, but I always find it useful to save the old battery, lest you need it later. Unless the battery is leaking, or poses some other health/safety issue, store it in a battery-safe environment.