1. Create a constituent export
2. Export Notes, Notes
3. In the Notes window, specify the number of notes to export per constituent
4. Enter the preferred dates in the Start and End Date fields
5. Click OK
6. Add other preferred fields to export
7. Click Export Now

If you only want to export the Last Note, select to export 2 Notes and select Order By Date and mark the option for Descending.  This will make the most recent note the first note and the second note can be ignored if not needed.  There must be 2 or more Notes to use the Order By function.