Power off the phone, and turn off all sounds
Remove the small screws on the bottom of the phone.
Slide the back of the case up. And pull straight off.
Remove small screw that is on the top of the battery connector and the antenna.
Lift up bracket and gently remove battery connector.
Using pull tab, gently pull the battery out.
When you are done, add the new battery and screw everything in place. Power it back up and you should be all set!