From Settings click 'Payment Terms':

As a Pro Member you'll see the Alternative Payment Terms section. Click 'create new terms' button

Name your new payment terms and complete the deposit step:

Next complete the trial step:

Finally complete the wedding final balance steps:

From a bride card select 'Use Alternative Payment Terms' from the Payment section dropdown:

Choose the new payment terms and click 'create':

The new payment breakdown will calculate based on the new payment terms: