Tell it as it was.

Leave the statue up but somewhere less prominent. Include a large plaque outlining what McDonald was famous for and infamous for. Tell the good that he did and the harm that he did. Make it clear that the statue does not exist to exalt MacDonald but simply to symbolize his role in Canadian history, good and bad.

I think it's better to reveal the man's policies and actions for better or worse, in a very public way, then to destroy the statue in the hope that doing so will help to destroy modern day racism directed at indigenous people. Because it won't. Use the statue as a teaching tool illuminating the realities and setting aside the myth.