1 press 9+pwr phone in boot mode.
2 connect by usb cable.
3 select right model or comport.
4 Click on DE-26 boot unlock (Force Mode) .
6 Plug out cable and reinsert battery .
7 Connect by RJ 45 cable .
8 Select right model or comport .
9 click on UART unlock .
Now your phone unlock enjoy ......
this is correct and batter for your post
no need to change other model like b309 or b319