We're going to cover each of those steps in a bit more detail below.
First, while it's possible to get into law school without an undergraduate degree, it's exceedingly rare. To get into the profession of law, you'll need to get a degree that will equip you with heightened reasoning skills, deductive abilities, solid writing skills (most of the work an attorney does is writing what the layperson calls "legalese") and generally provides you with detailed knowledge of a particular field that will be useful later on. For example, barristers working criminal cases usually get undergraduate degrees in law enforcement or criminology. Those working in patent fields try to get degrees in physics or chemistry, or, more recently, biology with a focus on genetics.
Good academics are important for getting into law school; the admission process is highly competitive. One of the hurdles you must overcome is passing the LSAT, or Legal Scholastic Aptitude Test. Different law schools in Canada will have different minimum levels on the LSAT that must be met, and you'll want to prepare for this as carefully as anything else you've ever done. Other things that can help you get into law school are serving as an intern or clerk with a judge in your province, or getting letters of recommendation from current members of your Provincial Law Society.
Once you've gotten into a Canadian law school, expect to work your tail off in trying to prove that you can become an attorney. (In Canadian parlance, an accredited lawyer may serve as either a barrister (appearing before the court) or as a solicitor (an attorney who specializes in legal documents and other formalisms). Unlike the U.K. where those two functions require different course preparations in law school, Canada follows a more cosmopolitan model. Many attorneys refer to law school as being one of the most grueling things they've ever undergone, in terms of the amount of work required to get the degree. You can also get a law degree at a U.S. law school, but take care. You need to make sure that the course equivalency requirements are met; there are significant differences between the way the U.S. and Canadian court systems and legal documentation requirements work. If your U.S. credentials are deemed sufficient, you'll be granted a certificate of qualification.
More difficult than law school is the provincial bar exam. Law school teaches you the thought processes of being an attorney, of keeping client confidentiality paramount, and keeping the legal separation of your feelings about a client and his merits as a human being distinct. (This is sometimes called the "legal void" thought process. A bar exam is a rigorous series of tests—both essay and standardized multiple choice—about the particular aspects of the law as they pertain to the jurisdiction of the province you're testing in. Most bar exams take two to three days to take, and applicants will spend months preparing for them. In addition to testing on the permutations of the laws in the books, the bar exam also covers professional ethics for attorneys.
Once you've passed the bar exam, the next step in the process is to present yourself to the Provincial Law Society as a supplicant for the right for a license to practice law. The Law Society will then aver and avow that the applicant is a person of worthy character and suitable for the practice of law within the province. There will then be licensing applications and fees to be paid, and being sworn in as an officer of the Provincial court.
Being an attorney in Canada is more than merely an opportunity to make money; it's a trust with the Canadian citizenry to serve the public good and the interests of your client. It's also a job that requires being meticulous and detail oriented, and focused on your profession.