Are you in Thailand , as if so you can do the process without going out. I had my elite visa approved while still on non imm type b. Had the visa cancelled and got the elite visa issued in my passport in Thailand
Do you file tax returns in Canada? As such your NOA ( notice of assessment) could be used to support your income. Not sure if the embassy in Bangkok could validate but you could ask them
Work permit cancelled first and on same day go to immigration to cancel your extension You will have leave the country by no later than 11.59 pm of the same day