It has to be done by a gunsmith recognized as such by the RCMP lab and the current dewat requirements are pretty universal no matter where you go.
The guidelines have not, AFAIK, been challenged in court and arguably exceed the legal standard. That said, a licensed gunsmith has to be used if you want to de-register something and they are not going to do anything other than an RCMP-style deactivation as they risk losing verifier status and potentially criminal charges.
As stencollector suggested try and find someone local that has been approved by the RCMP to do deactivations on FAs.
Both Marstar and Gunco in Nepean, Ontario are approved by the RCMP but if you are in Dartmouth this is probably not much help to you.
I know a gunsmith that had been deactivating FAs for years and sometime ago he lost his right to continue.
Perhaps the local RCMP people in your area can tell who has been approved for this type of work.
These days it is pretty simple---the guns are welded up so nothing moves.