Xiaomi Mi Band firmware update, downgrade

 Originally, I downgraded to restore screen brightness but no luck. If you like to change the original firmware then please follow these instruction. The original idea comes from here, but the instructions won't straightforward for me.

1. Download the right version of original Mi Fit App from here.
2. Open the .apk file with 7zip
3. Extract all firmware files (all files with .fw extensions) from original Mi Fit .apk with 7zip.
4. Copy all files to your phone internal storage
5. Install Notify for Mi Band app to onto your phone
6. Pair your band with the new app
7. Go to settings
8. At Bluetooth section click on Update
9. Choose the right firmware for your band. Guide to choose your firmware version
   
10. With the 'Choose file' button you can start the firmware change process
11. I checked the 'Alternative method 2' for successful firmware change
    

My Mi Band 2 was:

• HW revision v0.1.3.3
• SW:1.0.1.81

Than I downgraded to 1.0.1.69 with Mili_pro.fw without any luck. The display remains dark sadly.