To unselect the part-year resident status, I suggest deleting the state.
Also, make sure that in the My Info section before beginning the federal return, you didn't say that you had moved.
To delete the state, follow these steps:
- From the left menu, select State
- Continue
- New York click Delete
To re-add New York, from the same window where the state was deleted, click Add Another State and select New York.
Then, you should be able to go through the interview again without the part-year resident criteria.