Hello.

I have a European version of the F900 BT, which I suspect has a U.S. firmware.

Trying to install the EU version of the firmware, but fails to incorrect software.

Is there any way to remove the firmware?

you will probably have to do it manually instead of automatically by using testmode files to gain access to the system files.

 

 

disclaimer, not knowing exactly what you are doing will most likely result in a bricked system.