Done it. Very easy. When it was time to update my medical I called the head office in Montreal. They are very friendly and helpful. If they don't pick up, leave a message and they will call you back.
1. On the Transport Canada website it says you need a current Canadian Class 1 medical. There are several approved Canadian AME but I did it differently (it was approved by the head office of Transport Canada). I did my regular FAA class 1 medical (with hearing test - has to be original) + an EKG (has to be original) and sent it to the medical office of Transport Canada. Call to find out the name of the AME in charge. I misplaced his name. Two weeks later, I had a Canadian Class 1 medical at no charge.
2. I had to fill out paperwork for them to verify your FAA credentials. This process can take up to 3 months but bother them a little over the phone and they will get it done in a week. It is just a matter of how nice you are on the phone. Don't get too pushy. You will need to pay CAD 80 by credit card.
3. There are no skill tests (flying). None. Nada. Niet. All you have to do is arrange a time for you to take a 30 question test with a 60% pass rate for your ATP.
And here you have your ATP. That's it. How easy is that? It is just a formality and you have the spend the time with paperwork, phone calls and travel to Canada for your knowledge test. If you have travel benefits, in all it will cost you under $100 to do your conversion. Bling bling.