How to upgrade OS from USB drive?

First please download the OTA upgrade file (.zip format) from the link provided:

Be careful to download the correct one according to the model you have.

For Sbar: https://1drv.ms/u/s!AhNSVegWOv_mmVr6odpkjUJiCvFy?e=9U7WKh

File: rtk_kylin32-ota-1.0.25_0-overseas-20210514.zip (Size: 425M)

For Mbar: https://1drv.ms/u/s!AhNSVegWOv_mmHjXUrEbuLaB0Zmg?e=uYlqdg

File: rtk_kylin32_gk-ota-1.0.25_20210311-user.zip (Size: 369M)

Then copy it to your USB drive: 

1. Enter Home > System Settings ;

Choose About Us > System Version ;

3. Press Menu (gear icon) on the remote control (If it demands you to upgrade, press back on remote control first), the screen will show "More updates";

4. Choose Use the local update package, and it will show a folder;

5. If your USB drive is not shown in the left column, navigate the remote control to the 3-dots icon in the upper right corner, and choose Show SD card;

6. Then choose the .zip file in the folder, press it and start to upgrade.

It will take several minutes, please wait with patience.

Do NOT operate while it's upgrading to avoid errors.