A:Answer When I got my phone, I charged the battery and fired up the phone BEFORE inserting the SIM card. I connected to wifi at my home, logged into Google, skipped whatever it let me skip, eventually got to where I could have the phone search for an Android update, then had it do the update. After that was all done, I had the phone do a factory reset, which then went to Android 6. Then I shut it off, inserted the SIM card and went on with it.
CAVEAT: I'm not totally sure about all the features that are different with Android 6 compared to 5, but one gripe I have with 6 is that whenever you are near an open wifi network, the phone has an audible alert THAT YOU CAN'T SHUT OFF, at least not that I have found, even when it's not supposed to notify me of available public networks. On my phone, it sounds like an incoming text. I'm sure there are other features with 6 that I enjoy or are useful, but this is one "feature" that is an annoyance. Just FYI.