The right edge of the battery will give you the most leverage when removing the battery from the motherboard.
Use the pry tool to lift the edge of the battery. Remember: the battery is attached using adhesive.
You will meet a lot of resistance in this step. If the battery seems like it is pulling too much at the motherboard, try moving the tool along the edges to work the battery free.
Try not to rush. It is important that you don't ruin anything in the process of removing the battery. The battery will come free, it will just take some patience and finding the right spot to lift the battery free of the motherboard.