Remove back cover of htc pj83120 - Straight Talk LG840G Cell Phone

as htc M one 8 has an inbuilt battery you fist have to open the back cover and unscrew the back panel then you can remove the batteryu and replace it with the new one.

Removing the back cover

Securely hold HTC EVO 4G LTE facing down.
With your finger, pry open the back cover from the small opening near the POWER button.

Securely hold HTC One max facing down.
Slide the back cover lock down, and then lift the back cover from the side., replace battery then put cover back on

Try this! http://portables.about.com/od/otherdevices/ss/How-To-Remove-The-Back-Covers-Of-An-Htc-Inspire-4g-To-Access-Its-Battery-And-Cards_4.htm

Turn the phone over. Using your thumbs, push the back cover upwards. It should slide up with a little click. You can now remove the cover to get to the battery and the microsd slot.
Good luck.

Hi. Remove the battery cover then you can remove the battery. Here's how to remove the battery cover:

http://michaelquale.com/911134/how-to-remove-the-battery-cover-on-the-htc-hero/

Hi,
1. Remove the back cover.
2. Remove the stylus to reveal the RESET button that is located at the bottom of the stylus compartment.
3. Use the stylus tip to press the RESET button.
Your phone restarts and displays the Home screen.
4. Replace the back cover and insert the stylus back into its compartment.

1. Remove the back cover.
2. Remove the stylus to reveal the RESET button that is located at the bottom of the stylus compartment.
3. Use the stylus tip to press the RESET button.
Your phone restarts and displays the Home screen.
4. Replace the back cover and insert the stylus back into its compartment.

To remove the back cover, first make sure the phone is turned off. Hold the device securely with the front facing down, then, with your thumb or finger, lift up the top of the back cover.

For more detailed steps and illustrations, you can download the Quick User Guide here:

http://www.htc.com/hero/m/files/guides/090703_Hero_HTC_English_QSG.pdf

You have to remove the back cover, and on the left hand side there is a removeble cover (the silver strip on the side of the phone). When you remove that, you will see on the left the sim card. Press it in with you finger nai and voila.