Before opening up your laptop, you’ll want to purchase the correct battery by looking up your computer model on a third-party site such as Batteries Plus and using the tools to find the brand, series, and exact model of your laptop. Once you’ve landed on the battery type, voltage, and capacity, you can buy it from shop around.
Replacing the battery on every computer is different, but you will always have to unscrew the bottom housing using a Phillips screwdriver with a small head. A standard 01 Phillips head is often too big for laptops, so I use a magnetized 00 head from this pack of bits and pair it with my Black+Decker electric screwdriver for the job.
From there, you will need to apply pressure to pull the back frame off of your laptop. Some people recommend dedicated plastic pries, but I just insert a thin ID card (a credit card or license will do) into the exposed seam and slowly pry open a gap along the edges. After the frame has been separated I gently pull it off using my hands to expose the internals and heat sinks.
Carefully remove the white connector of the battery wiring harness (indicated by the multi-colored wires) from the computer to detach the battery. The black battery is usually held in place by an adhesive similar to double-sided tape—carefully pop it up and out. Take note of the orientation of the wiring harness so that you can easily plug it back into the connector. (With the battery detached and your component slots exposed, this is the optimal time to slot in any additional upgrades you had in mind, say an additional RAM stick or a new SSD.)
Align the fresh battery within the space left by its predecessor. Apply light pressure and reconnect the wiring harness to click it back into the computer.
Reassemble your laptop and turn it on to check that it’s receiving power. If you’ve added RAM or additional storage, you can use Task Manager (CTRL+ALT+DEL) on Windows or System Information on Mac to verify that the computer recognizes the larger memory and storage space.