receive 1s today
do not have the symptom that bluecat68 was saying,
perhaps its lemon ?

quite good the build quality
was having a tough time getting the back cover off, despite
enormous strength the phone did not flex whatsoever

press slightly on the center of the phone with your thumb
then gently peel on the usb port there
its on the manual

hope this helps 

If you look to the right of your phone, you should see a hole for your thumbnail to pry.
First lift it up slightly. Next, use your finger and pry the case up. Thats all