All good info here, but you need to plan ahead.
What I did was go to Algonquin College in Ottawa and took the 2 day weekend air brake course. It includes the written and practical test and the instructor provided the certificate you take to the license office to get the Z endorsement. Cost of the course was around $200. That took me to GZ on my license.
Next I needed to get the "D".
The most important part is that you need to have a medical first from your doctor - around 75$. I only found this out during the air brake course.
Problem is if you have had any past medical issues, your doctor's word is not good enough and it has to be reviewed by "their" doctor - and that can take up to six weeks. (mine took longer because the local license office did not fax off the paperwork - after six weeks I ended up talking to the head office in Toronto and faxed it off myself but to give credit where it is due, I had their doctors approval within 24 hours after that.)
That allowed me to do the written test - actually the questions were much more geared to "G" class and there was nothing specific for "D" that I recall.
Next I had to book a "D" class practical drivers exam - not every center can perform the test. I had to go to Cornwall or wait a few more weeks for closer centres - you can book on-line and see availability.
Then I had a neighbour with a Class "A" licence accompany me in the MH to Cornwall. There I had to do the "pre-trip" walk-around/inspection and then drive through the town and on and off the highway(401). At the end I had to back up between two posts (I asked the examiner to exit and be the ground guide which is recommended but they can decline).Total time for the practical about 15 minutes.
Next it took two hours to update the computer to issue my temporary "DZ". Seems my account was locked for some reason and required a supervisor over-ride to unlock(supervisor was at lunch).
I started the process in June (with the air brake course) and got the DZ endorsement in September!
As far as I know, every 5 years I will require a medical and have to write the air brake test again. On the plus side I can always drive a dump truck to make a living now:B.
So it can be a long process, especially if the bureaucracy fails like it did with me. Plan ahead and you might need some patience.:Z
And yes, I did drive the MH during the summer without the "D" endorsement - I have had lots of experience driving heavy machinery while I was in the army and have used air brakes since I was sixteen.
2008 Holiday Rambler Scepter 42 PDQ
2018 Ford Edge SEL- Ready Brute Elite Tow Bar/Blue Ox Base plate/Patriot Brake System
Retired Canadian Army WO (1971-2000)