When handling the battery, avoid squeezing or touching the four exposed lithium polymer cells.

Lift the battery from its edge nearest the logic board and remove it from the upper case.

If you're installing a new battery, you should calibrate it after installation:

Charge it to 100%, and then keep charging it for at least 2 more hours. Then, unplug and use it normally to drain the battery. When you see the low battery warning, save your work, and keep your laptop on until it goes to sleep due to low battery. Wait at least 5 hours, then charge your laptop uninterrupted to 100%.

If you notice any unusual behavior or problems after installing your new battery, you may need to reset your MacBook's SMC.

The replacement battery may arrive with plastic liners and films. The plastic film is easily removable and should be removed before installation. The liner is thicker and acts as a layer of defense against punctures. Do not remove the liner from the battery.