Comment 7 for bug 1331813

One key step is making sure that ofono is stopped before editing/replacing the gprs settings file. If ofono is running, any changes made will be ignored.

Regarding adb permission problems, you may need to run adb shell, then use sudo to move the new file into place ( again after stopping ofono ).

This has been proven to work, so you just need to ensure you carefully follow that steps in comment #1. Finally, another alternative is to purchase a SIM from a different carrier.

Also we're going to make a change which will automatically make this conversion happen, as IPv6 isn't on our short-term work list.