All day I've been singing "emancipate yourself from mental slavery/none but ourselves can free our minds," and while singing I've reached the conclusion that, while the line works well as an exhortation to people to do what they can to free their minds, it is strictly speaking, not even close to being true.
Start by remembering what a free mind is. A mind is free if it is not bound by an inherited set of ideas, but is able to consider the widest range of possibilities. Most importantly, a free mind is not trapped by beliefs that justify existing unjust power structures, and can conceive of better alternatives. A free mind has imagination and skepticism.
Honestly, you can't just will yourself to have imagination and skepticism. The main source of imagination and skepticism isn't in you at all. It is in the way you were raised. And while it is possible to develop imagination and skepticism later in life, this too will be largely a product of your experience. The main internal cause for increased imagination and skepticism would be a kind of second order disposition. If imagination and skepticism are themselves dispositions to think a certain way, we can also talk about a disposition to cultivate those dispositions. But once you are in a position to have such a disposition, you pretty much have all you need to be imaginative and skeptical.
Once you have the will to free your mind, your mind is already free.