Is it possible to update to MM on S6 without a SIM card?

[MetalKore]

I have switched from the S6 (AT&T G920A) to S7 Edge, but I would like to update the S6 to MM so that my wife can use it. It is currently on 5.1.1 but I do not have a SIM for it. The SIM card from wife's current phone will not work in the S6. Do I need to get a new SIM from AT&T to update the S6?
Thanks in advance for any help.

 

[SpookDroid]

It depends. Not sure about the S6, but AT&T IS notorious for limiting updates on their carrier-branded devices to having an AT&T SIM inserted.
However, if the update exists, you can get it without a SIM at most Best Buys (on their Samsung Experience area).

 

[MetalKore]

Thank you for the tip!!!

 

[SpookDroid]

No problem! You can still try it via WiFi, though...maybe it works and it saves you a trip to BB, but if it doesn't, at least you have that option.