Exif Farm - how to export / import EXIF data to / from XML file(s)
To change Exif data of the fields not editable in the Exif Farm program:
1. Export Exif data to XML files. This will also allow to create any electronic document with your Exif data, for instance an Excel spreadsheet, using data import function of requested aplication.
To export Exif data to XML files right-click selected files*, choose "Exif Info" item and then click "Export Exif to XML" from the context menu:

2. Use any XML editor to change your data. Then re-import Exif data from the edited XML file back to your graphic file after you have cleared original Exif data of the file.
To import Exif data from an XML file right-click selected file, choose "Exif Info" item and then click "Import Exif from XML" from the context menu:

To avoid undesirable change of EXIF data, please, make backup copies of files before editing.
* Batch editing is available in the registered version only.