The lawyer in question makes an application and there is a committee in place at the Office of the Commissioner of Federal Judicial Affairs. The committee is composed of citizens and judges. The committee reviews applications and decides whether or not the person is qualified. In addition, the candidate indicates in his or her application that he or she wishes to be appointed to the Federal Court, the Canada Tax Court, or the provincial Superior Court. To my knowledge, the minister then asks for a list of people deemed qualified, and they are appointed as judges.
On December 12th, 2006. See this statement in context.