Macbook was lying about the battery

crwdns2853023:0crwdne2853023:0

The OS and charger light would indicate the battery was charging, but it wasn't. For example, it would report 85% then if I unplugged it would suddenly drop to 10%. Sometimes, when I thought I had plenty of charge, the battery would completely go dead and the the laptop turn off.

crwdns2853024:0crwdne2853024:0

Many steps, but easy to follow.

crwdns2853025:0crwdne2853025:0

Use an egg carton to sort the screws by step. If you don't have a spudger, whittle one out of a chopstick.