Windshield air vent

[SpookyTheFirst]

Hello,

I have this part on my F360 that came off (both sides), got one new, but anyone does how to put it in place? Mechanics says it should be screwed underneath, which means totally unmounting the dashboard...

Thanks!

[SpookyTheFirst]

I was considering putting silicon glue in the holes and put the part under pressure during drying with some foam stuck against the windshield...