Chosen Solution
I have a question for you I don’t see tap on iPhone 6 battery Update (02/20/2018)
I don’t see tap on the battery to remove it
No battery adhesive tabs as I can see which would mean the battery has been replaced before but without the tabs. You will need to remove the screen first, unplug the battery then pry the battery using a non-sharp spudger like tool at the bottom left middle left of the battery Don’t pry the upper part or near the volume button area as the cable goes right under the battery and you can tear it. Personally I just use a metal spudger and carefully work my way of prying the battery from the bottom left / left hand side.
like Ben said, no adhesive strips means it has been replaced before. depending on the type of adhesive whoever replaced it before used, it might be easy to remove. DO NOT use metal to pry it up since you run the risk of puncturing the battery. Do remove the screen prior, this will make it easier for you. I usually use a black spudger dipped in alcohol works amazingly, since the alcohol spreads under the battery and loosens up the adhesive.
