Official certification (Thor Rom)
1.Download the ROM file via above link; copy and paste the ROM file to internal storage;
2. Click “Setting” icon -> “About Phone”->“wireless update”, then click the icon at the top right corner, and choose “Local updates”;
3.Click into “internal storage”, find the ROM file and choose it;
4.Click “install now” and a POP box appears; choose “OK” to update.
5.It’s going to be finished soon.During this peroid,you device will be rebooted.