I have been looking on this site, & I just can't find any answers.
Solved! Go to Solution.
I checked the user guide for that device. And it says, slide the battery cover upward and remove the battery cover from the back of the phone.
If you still are unable to remove the battery you might want to visit a service and repair location www.sprint.com/storelocator?ECID=SM:BW:2011084TORELOCATOR.