The battery in my iPhone 6 wouldn't hold a charge and then started to not even take a charge...so, I decided to change the battery to correct the problem.
The repair was relatively easy. I used the warming pad from a previous iPad repair kit to warm up the bottom of the phone to help release the adhesive strips. I unscrewed the two pentalobe screws at the bottom of the phone with the screwdriver supplies in the repair kit. I opened the phone an unscrewed the plate holding the battery connector and used the included spudger to lift off the connecter. There was a small issue with the adhesive strips pull tabs as they broke about 1/4 of the way from the top. The result was that I had to bend the battery slightly to get the tweezers supplied in the repair kit to grab the white adhesive strip and pull them out completely to remove the battery. I then applied the replacement adhesive strips to the new battery and placed carefully in the case. I did have a little difficulty reconnecting the battery connector. I was expecting it to snap back into the socket. However, the thin padding on top to the connector made it more challenging. So I carefully removed the cushion with t the tweezers and put it aside, placed the connecter in the socket and replaced the pad being careful not to move the connector. I screwed the plate over the connector and turned the phone on to make sure the connection was secure. Once I was satisfied that the connection worked I clipped the screen back down from the top down and then replaced the screws in the bottom.
When removing the pull tabs from the adhesive straps from the top of the bottom of the battery (does that make sense?) be sure to grab the white adhesive with the black protective cover. This will probably prevent the issue I had. Also, removing the protective padding on the battery connector will make it easier to plug it back into its connector on reassembly. Don't forget to put the padding back on!