First of all, anytime you are dealing with a deportation order it's best to hire the services of a lawyer as that complicates your case greatly.
An authorization to return to Canada will cost you $400 which is non-refundable in the event the application is refused. I believe you need to also include the completed visa application form, 2 passport sized photos, and a copy of your passport.
http://www.canadainternational.gc.ca/mexico-mexique/visas/fees-frais.aspx?lang=eng&view=d
Immigration Forum
