Great experience installing new iPhone 6 Plus battery from iFixit!
My 2+ year old iPhone 6 Plus had a failing battery. The Apple Store wants a fair amount of money to replace the battery and I wanted a more economical solution.
After reading and watching the battery replacement video I ordered two battery replacement kits for my iPhone 6 Plus for my wife and I. I was a little nervous about the first replacement but it went very smooth. You do need to be very careful, patient, and detailed. The screws are very tiny and the cables are somewhat fragile.
Please do not go into this repair as if you were a bull in a china shop. Take you time and read, re-read, and triple read if you have any doubts. I used the single suction cup to remove the display as described. It's definitely a little stressful and choosing where to put the spudger in to pry it open is confusing as you don't want to hurt the button assembly. Once you have a couple of the screen clips released it's very easy to completely remove the display. Lastly, take your time pulling the battery adhesive tabs! SLOW and steady and they will come out just fine. I was too quick on one and it broke.