On Schedule E rental house property I have entered 365 days of rental use but 365 days of personal use also appears. How do I remove the latter?

Why don't you just clear both fields and check the box that says it was rented all year?

All you should have to do is work back through the rental and select the option to indicate it was rented the whole year. Then, if asked for personal use days, enter zero.

Even after selecting the option it was rented all year, there are situations where you "could" be asked for personal use days. So if this fits your situation, make sure you enter zero for personal use days.