How does someone 'free themselves' of something that exists only in the mind of other people?
a.) It doesn't only exist in the mind of other people. The fact that you don't consciously think of yourself as white doesn't mean you're not affected by the construction of whiteness. Here, do this and report back.
b.) Same way any social sea change happens, by educating oneself so one can educate others, and maybe eventually we improve on a societal level.