Upgrade S5 to 6.1 or 6.0 Marshmallow
Sorry if this has been posted already but I can't find a direct answer. I recently signed up for the free service for my son. I bought the S5 for $120 deal and it said it was able to be upgraded to 6.0 but every time I try via the OTA method it says the device is at the latest version. How do I upgrade without impacting my free service?