Download brotli.exe for windows. https://bayden.com/dl/Brotli.exe
- Create new folder on desktop. Extract your rom's new.dat.br file and move brotli.exe to this folder.
- Hold shift button and left click anywhere and click "Open CMD window here"
- Copy and paste following code in CMD window
brotli.exe --decompress --in system.new.dat.br --out system.new.dat