Good morning John, i have removed the front number plate box on our Six, so it should be very similar to yours.
It was just a case of removing the number plate and then there are the two threaded bolts behind the plate to undo and off it came.


Dave
Plus Six "Squeak"
Roadster departed.
1936 BSA Empire Star Q8. 1935 BSA W7-35. 1938 BSA M20