I don't believe there is another way without root. But I'm not an expertThanks, I found your post but in my initial question a few pages back I explained that I don't have root (and don't really want it) so I cannot do this. That's why I asked of this can also be fixed with an ota or something.
If not, I'll have to choose if I want root and volte or no root and no volte..
edit: You can also root, make the changes, and unroot