The full quote is emancipate yourselves from mental slavery, none but ourselves can free our minds.
Each of us is responsible for working to free our minds from the negative messages we have internalized from our society and our families.
Weather you are black or white, you will need to unlearn the racist thing our society has taught you about yourself and others. It is up to each of us to do the work, and by this point, there is a ton of information out there in the form of books, articles, podcasts, movies and tv shows to help inform you.
Weather you are a man or a woman you are responsible for undoing the conditioning society has used to shape your assumptions of what it means to be a man or a woman, and weather or not you can conceive or accept that there are more than two options.
And if you grew up in an abusive, neglectful, dysfunctional or chaotic home, it is up to you to free your mind from the negative messages that may have bee given to you by word or deed about who you are, what love looks like, etc.
Get into therapy, you and the world are so much more than you have been led to believe.