As others have said you'll need to disable it currently. Then follow the steps that you used when you initially set it up for the new device.
When the day becomes the night and the sky becomes the sea, when the clock strikes heavy and there’s no time for tea; and in our darkest hour, before my final rhyme, she will come back home to Wonderland and turn back the hands of time.
Perhaps some feedback for the team - add some guidance notes on the website or the ability to re-scan the code, without having to disable it (making your account temporarily vulnerable)