Can I do this from Canada?

[laughter]

Hello Johnny! To answer your question....yes, it's possible for international students.

I'm hoping to get a bachelors in business, marketing would be ideal.

There are several things to consider here....
Do you want to complete your whole degree via online learning and credit-by-exams OR are you seeking to transfer to a brick-and-mortar college later?
What are you looking for in a degree - speed, cost, prestige, etc?
Most students here enroll in one of the Big 3 colleges, namely Thomas Edison State College, Excelsior College, or Charter Oak State College, as they are currently the most accommodating in terms of transfer credits.
Another thing to consider would be... have you earned any college credits? If yes, you might want to check how they transfer to your target college.

Do I just figure out what clep exams the program I want requires and start doing them?

Once you've figured out which college you're going with, get a copy of their credit breakdown for a business degree in marketing. (i.e. TESC's BSBA in Marketing BSBA in Marketing Degree Program)
Next, plan the courses/exams you wish to take and align them to the degree plan. You may utilize CLEPs, DSSTs, UExcels, StraighterLine, Saylor, ALEKS, TEEX, NFA, etc. depending on which college you are enrolling in.
Once you've worked that out, post a copy of the degree plan here and get feedback from other members.
As you move along, keep asking questions. You'll get a hold of how this whole thingy works before you know it.