Theres a notch at the bottom left side of the device

You can simply pull up on the back cover with your fingernail

Theres a notch just above the battery, where you can pull the battery out

There are 6 phillips screws around the cover (circled in the image)

After removing the screws, insert an opening pick from the right side of the device

Drag the tool upwards

Once you reach the edge of the cover, pull the tool towards you

You should hear a click, and should be able to pull the cover off

You can simply pull the PCB towards you