One note to add is that the original battery connector's top was glued to the motherboard cover. I had to remove the battery before I could successfully sepearte the 2. My phone is still working and I'm charging it right now! :)
Thanks for the very detailed guide.
Thank you! I use a slim (but not sharp) butter knife to nudge the battery out slowly by poking the adhesive tape along its length. It was a bit unnerving because I was afraid of damaging the soft battery. Worked out in the end.