Battery replacement is fairly simple. All one must do is orient the camera so that the battery slot is visible, slide one's thumb across the battery compartment (some elbow grease is required), and it will pop open. Reasons why one may want to replace batteries are: 1) if the camera will not turn on; 2) if the camera is not functioning to its full capacity.
With the camera facing LCD side up, slide the battery compartment lid to the right.
Remove old batteries.