Change to what? That is the due date. And if it's already been efiled you can't change anything.

If you have not yet transmitted the return and want to change the payment date, go to Misc. Info./Direct Deposit and look for Electronic payment date [Override]

OR if not electronic payment go to Letter > Due date of return [Override]

If you have already transmitted, you just get to live with what you have done and learn from it.