Welcome to the community!
You can change the number the same way you did the first time. If no 416 numbers are available you will have to keep checking until some becomes available. I would suggest you try first thing in the mornings.
Hey there @jason34434E,
How many times have you changed your number or attempted to? You've also mentioned speaking with call center representative, where they able to assist you with changing the number? Keep in mind that changing your number is subject to a $35 fee, though it's free if you do it online. you can find more info here.
Make sure that you're also logged in as the account holder on Fido.ca to be able to change your phone number.
Let us know!