I would choose to amend the Official Languages Act. That seems to me to be easiest and clearest under the circumstances. The Supreme Court itself renders decisions recognizing that bilingualism is a fundamental value of Canadian society and supporting the idea of moving towards the equality of both languages, not just in theory, but also in practice.
So, if we are actually supposed to move towards the equality of the two official languages, imagine if bilingualism is not required from those who want to be appointed to the Supreme Court of Canada. It seems to me that it contradicts the Supreme Court's own jurisprudence.