...over here in NZ you either get your camera/lenses/etc repaired at the officially with Canon, etc, or you sent it to "that guy." There are only a handful of " that guys" in the country, they've spent literally decades building a reputation and their names are mentioned in hushed tones. In Wellington, that guy was Phil Jacobs. He spent 40 years as a camera repair tech, and if any photographer in Wellington was looking for a repair guy Phil was the guy that got recommended. Phil was a tinkerer who figured out how things worked.
Sadly Phil got struck down with a terminal illness a couple of years ago, and he passed away in September 2013.
If things need fixing now: I send them to Timaru, which is on another Island to the one I'm on. I'm in the capital city with a population over 300,000, and there isn't a camera repair shop here with a rep for any of the professionals to trust.
As suggested by Snafoo, this is the biggest thing your facing. There is a demand for this sort of work. (When I sent my lens down south, it took him a week to be able to simply look at my lens he was so backlogged.) But you've got no track record, no reputation, no experience. It takes years to learn this craft. It takes longer to build a reputation. I'm not going to send thousands of dollars of mission critical equipment to someone who isn't proven.
So if you are serious about this: then I would suggest that you settle in for the long haul. Its doable: but it isn't something you can do half hearted.