Attach the new battery by inserting the end of the orange power connector (the end not attached to the battery) clips into a little socket on the device (it's barely visible). You can tell when it clips in by the feel and sound. Make sure that when you put the new battery in, you first clip the connector in before you stick the tape down.

Be Aware: Your new battery might not be charged, so it may not power-on immediately! After replacing the battery, plug your Oasis in and let the battery charge to full capacity.