Can we downgrade from 5.1.1 to 5.1.1 but different build.

I wanted to know if i can flash the G920IDVU2COf8 from the new G920IDVU2COGA? I am currently on the latest update G920IDVU2COGA and wanted to go back to G920IDVU2COf8. Pls help.
Thanks. :)