Adjust payment on account before submitting

Hi, I entered my return and have just come back to it to adjust the payment on account figure before submitting (I needed to check and actually it is a lot lower than I had originally entered). I can't see how to do that in the "tailor your return" screen(s). Is there a way of doing that without deleting the whole return and starting again? Thanks.

Hi,

This is not at the tailor your return section but further on after the view your calculaton section.

Thank you.