@blackritz If you submitted your return, you will need to wait till it has been accepted or rejected. If it has been accepted, then you can start the amend process. If it is rejected, you will have the opportunity to make the change then re-submit.
You can amend your return from your Tax Home. Scroll down the page to "Your tax returns and documents" then select the "Show". Select the tax year then you will be able to select the Amend Return option.
