I Just replaced my old battery with the one from iFixit, was super easy with the iFixit instructions. The new battery was at 50% charged out of the box, and is now charged to 100%, took about 2 hours.
I have one question now. Are there any special instructions for the first charging cycle of a new battery? I ask this because I just remembered that on old Macbooks one had to do some some kind of "calibration" for maximal battery life, which involved something like charging the new battery to 100% and then letting it discharge down to 0%. Do we still have to do it on these new models?
Thanks for any inputs,