Change amount of tax return document already submitted to SARS

I have already submitted my tax return for the year 2015, but I want to correct the amount on source code 4006. Can you please assist urgently to correct that. How do I make a correction on TaxTim?

If you login to TaxTim and view the status of your tax return, you will see a 'Request correction' button. If you click that, you can go back into the TaxTim Q&A and make changes to your answers (just remember to press Save after each edit). Then you can resubmit your tax return with everything correct and it will go through to SARS as a revision.