Switching Apple ID?
My sister (not tech savvy at all), her husband just passed away. He had the 2013 Mac Air set up with his ID, hadn't upgraded his laptop from OS X Mavericks. I can't get into his ID because it asks to verify with a text code, and she cancelled his phone. How do I help her change to her ID so she can access the App Store? Thanks. /Michael.
MacBook Air