Editing an existing HARA file uses the same dialog as creating a new file.
Right-click an .sxha file, bringing up the Edit HARA option.
Outcome: the Edit HARA dialog will open, displaying the existing information for your HARA file.
Make changes to your HARA as the case may require and click on Continue.
As suggested by the screenshot above, the HARA Configuration is set as a constant at HARA creation time and is not subject to editing.
Outcome: the second Edit HARA dialog will follow, proffering selection of System Elements for your HARA file.
Check the appropriate boxes and Save Changes.