We were in the same boat as you - wife was in Canada on visitor visa - we just followed the instructions, as
@armoured also mentioned. We let them know of the change in address, and did the same on ECAS ( although I did this as soon as she landed in Canada ). They then sent us a separate email with instructions.
Thanks for replying. Glad to hear that things worked out for you!
We probably should have notified of our change in address as soon as we arrived in July, but we weren't sure if the pr would be finalized and approved before we were scheduled to return to Thailand, so we didn't. Now that it has been, it makes more sense to stay put here. So now that we have been approved, the email message instructs us to send the passport to Singapore for a visa stamp. However, in the appendix A of the document "how to submit your passport, photos and appendix b' there are instructions for both people residing inside of Canada and outside of Canada.
I guess the crux of the matter is that while we are residing inside of Canada, because we haven't notified, they believe us to be residing outside of Canada, so I am just uncertain of whether or not there will be a problem with us just using the instructions for applicants residing in Canada.
I did send an email to Singapore explaining this situation, but received a form email in reply, indicating that I might not get a response.
I think what I should probably do is notify of the change of address now, and then use the instructions for applicants residing in Canada.