Here's how:
- Sign into your return, scroll down until you see "add a state" (this will not actually add a state, it will simply get you back to your return)
- On the left select "state", then "edit" beside the state
- Each state is different, however estimated payments are usually under "Other situations"
Note: If you make changes to anything other than estimated payments it could affect your previous entries. They will not refile, but will give you an incorrect view of your return.