Remove the back panel of the device by taking out the seven screws on the back panel of the device.
Four of the screws are under the rubber feet so they will need to be removed. To remove the feet, pry them off with the spudger.
Remove the seven screws that are holding in the battery. They can be seen circled in the picture.
When unscrewed, lift the battery. There will be a cable connected to the battery. Detach this cable from the board and remove the battery.
Attach the replacement battery cable to the board and reassemble. It can be seen highlighted in picture 2.
*Note: When reinserting the battery it is easier to put in the long end first and then dropping the other side in.