My Human Sentinel character has a trait that I'd like to get rid of, but can't figure out how to.

I could just ignore it, but it's annoying to see it. Basically, Sentinels are given a single spell cantrip, but I want my character to be magically inept.  

Is there any way to edit my sub race and remove his image spell casting ability?

Any tips you have are appreciated.

I realize this isn't exactly a 'tech support' question, but I couldn't find a better place to post this. Sorry.