I changed mine today with a normal hard case battery with the same exact specifications. I left it turned off until the battery charged. Then I turned it on and connected to it That was 3pm, it’s 9:26pm now and it’s only 1/2 way drained 2 of 4 bars left. The steps I took:
I turned it off, removed the SIM card & tray.
Took the back cover off.
Started with a thin plastic Key Chain card (those small membership cards like Rite Aid etc.) it’s small and you can maneuver it around.
I worked it under each corner then worked inward until I had it pretty well loosened.
Then I used a full sized (wallet sized) plastic card.
It popped right out.
Then I used a small philips screw driver to remove the 4 visible screws.
There is 1 more screw that has a felt like cover over it. Once that one is out carefully separate front panel it clicks in & out just like the back cover.
Once that is off you’ll see the plug with the 3 wires Red top green middle black bottom.
The plug is snug and lifts off. It doesn’t slid off. The bottom of the plug/connector is slotted so it pops off.
Then put the new battery in guide the plug & wires through the hole, line up the connector red wire top and press down on the plug and it will pop into place.
Put the front cover back on. Turn it on to make sure it’s working, turn it back off, then put the screws back in. I put the felt cover back on the covered screw. It probably there for a reason like preventing shorts or something.
Put the back cover back on.
Put the SIM card tray back in.
Plug it into the charger with the unit off until it charges to 100%.
Remove the charger, turn it on and your good to go.