Chosen Solution
I’ve been told using isopropyl alcohol on the white adhesives are the best way to make it easier to come off. Also when doing battery replacements for iPhone 6 always take off the vibrator motor as it makes it easier to remove with the pull tabs, when you start pulling, start grabbing the white part instead of the black tabs as the adhesive tends to separate from the black tabs. If the adhesive pulling are no good, you’ll have to start prying with a metal spider on the middle left and bottom left, away from the volume cable area without bending it too much.
Usually you can lift the battery up enough to grab the adhesive under the battery and resume pulling it out from the bottom. Other than that, you made need to commence the “pry of shame.” New battery may be in handy.
I can halp your to remove the iPhone 6 battery buy iSesamo Opening Tool and use Prying and Opening Tool Assortment and I use Metal Spudger
We have this happen some times . If you can not use tweezers to regrab the adhesive then use a plastic pry tool and heat to slowly slide it down under the battery to pry it loose.
Thanks for all the answers. This took way too many frustrating hours, but in the end, I had to do the infamous pry of shame. Removing the vibrator help. Then as I placed the battery in, the connector wasn’t folded correctly to seat on the socket. This took another hour or two as the adhesives were already in. Then, doing the screen connectors took quite some time. In the end, I haven’t noticed tooooo much of a difference in the battery, but there’s some pros I’ve noticed in the time I’m using it. I feel the guide on removing the adhesives could use some tweaking though. These adhesives are a soab and don’t come out easily.