Brandy, I used to have the same problem as you, the easiest way I have found is to push at the top of the cover (near the camera) where there is an arrow, push in the direction of the arrow. Make sure you are only pushing the cover not the whole phone. The cover should slide down and you can then remove it.
I used to use the method of pushing up from the speaker, but I nearly snapped the cover in half once so I decided to find an easier safer way, and that is what I found.
By the way, the battery cover is actually the entire back plate of the phone, I know some phones only use a small portion as the battery cover, not this one.... lol