Continue swinging open the back panel until you can rest it on the left edge the phone, being careful not to put any stress on the attached ribbon cable.
During reassembly, this is a good point to power on your phone and test all functions before re-sealing the back panel. Be sure to power your phone back down completely before you continue working.
Whenever you use the spudger near the battery, be very careful not to puncture the battery.
Using the pointed end of a spudger, pry the battery connector straight up from the motherboard to disconnect the battery.
To re-attach press connectors like this one, carefully align and press down on one side until it clicks into place, then repeat on the other side. Do not press down on the middle. If the connector is misaligned, the pins can bend, causing permanent damage.
Continue firmly pulling up on the adhesive strip with constant force. If you're using a spudger, spin it every so often to keep the exposed section of the pull tab as short as possible.
This may take a lot of force.
These adhesive pull tabs are very prone to snapping in half during this process. Pull as slowly as possible.
If the adhesive pull tabs are not stretching, fill a plastic dropper or syringe with high concentration (>90%) isopropyl alcohol and apply a few drops under the left edge of the battery. Give the alcohol a minute to weaken the battery adhesive.
Continue this process for each of the three pull tabs, until all are either out or have snapped in half.
If the battery tabs snapped during removal, insert an opening pick on the upper right edge of the battery, slicing the adhesive underneath.
Even if you successfully removed all three adhesive pull tabs, using an opening pick to dislodge the battery may be helpful.
Don't insert the opening pick on or anywhere below the grip sensor cable, as the pick can damage the charge port flex cable located underneath the battery.
Do not reuse the battery if it has been deformed or damaged, as doing so is a potential safety hazard. Replace it with a new battery.
Lift the battery up and away from the phone to remove it. You may need to peel the battery away from any leftover adhesive tabs.
If there's any alcohol solution remaining in the phone, carefully wipe it off with a lint-free cloth or allow it to air dry before installing your battery.
To install a replacement battery:
If you're using stretch release adhesive, apply them onto the battery. Otherwise, apply some double-sided tape, or pre-cut adhesive strips in the phone's battery well, being careful not to cover the charge port flex cable. Peel away any tape liners to expose the adhesive.
Temporarily re-connect the battery's connector to the motherboard socket. This ensures that the battery is properly positioned.
Lay the battery in place and press firmly.
Disconnect the battery connector from its motherboard socket and resume re-assembly.
Slowly lift out the motherboard, being careful not to snag any ribbon cable connectors.
The rear-facing camera module connectors loop around the motherboard, and the camera module is not secured to the phone, so it may lift out with the motherboard during this step.
Completely remove the motherboard.
When reinstalling the motherboard, check that no ribbon cable connectors are caught underneath.
