Entered 365 days for property personal use on the schedule E. However, I have 32 rental days. So I need to edit the personal use days but the system won't let me.

Navigate back to the rental property section. 

On the page, Was this Property rented for all of 2016?, select 'No', to open up the dialog box. Enter the rental use days and the personal use days.

Note: The personal use days means did you use the rental personally after it was placed in service (like a vacation property). Enter '0' if you did not use the property yourself after it was placed in service.

Also, indicate whether you rented a part of your home, or converted the property from personal use on the page, Do Any of These Situations Apply to This Property? 

See examples.