F9 First Persoon View Key

[Ragnaroeker]

I am not sure if I am putting this in the right place or not. I having dabbing in changing the UI as a hobby for about a year. I am basically clueless, I just love computer programs. However, I have had 4 people this week ask me how to disable the F9 first person view key so they can use it for something else. I have searched thru every xml file and I can't find anything that to me looks like this command.

I am clueless like I said, so please forgive the newb question, but if I can help these people that would be nice. Is there a way to do this and if so can you just point me in the right direction?

Thank you very much.