first of all, I would suggest to take it to a repair shop if you have never done a laptop repair. many things can go wrong. However, if you insist in doing it yourself, it is good idea to go to Youtube and search for "how to replace battery on " Dell/HP model number " . you should be able to find a video that can guide you through it. Usually, first you need to unscrew the screws on the bottom casing, and then taking out the keyboard, removing screws behind the keyboard and then remove the top casing and finally replacing the battery.
