Thanks for getting back to us. You would need a technician appointment in order to swap your modem to prevent service interruptions that occur when using other methods. If your modem is suspected of causing intermittent issues, this will ensure that you do not lose service while waiting for your replacement unit.
You would have to go through our Technical Support for the modem swap and to set up an appointment, you can reach them at 1-888-236-FIDO (3436).
Hope this helps!