Thank you iFixit for such up close photos. This really allowed me to perform this task myself. Truly appreciate it!!
These last 3 screws were a bit** to get off. One of them actually would not come out but I managed to slip the battery out anyways. Maybe it nudged just enough. Getting it back in was okay, just slid it under. Fit was snug, had to be careful not to break or crimp the ribbon in front of the battery connector, as Joel stated. Simply snipped a piece of the plastic tab from the old battery and stood it up in this spot and slid the battery down, this kept the ribbon from crimping. Only one of these last 3 screws that I did get out, did I put back in. Not sure why they are there as the tabs that hold them are enough to hold the battery. All other screws and battery connector worked like a charm. Replaced the cover, turn it on and Whala!!! Only got a message that said I needed to reset the Date & Time. Got it on the charger now, as new battery only had 75% charge, so fingers crossed it will recharge at a 100% and last longer than the old battery before it's next charge. Good luck everyone!!