You can amend the non-key fields of an interest (Agreement date, term, type, etc). To do this simply hover over the 'registrations' item and select the interest type, then from the options, select AMEND.
You can enter a combination of the VRM, VIN and Agreement reference number or just one field to retrieve the interest you wish to amend. Please note however if multiple records are found you may need to refine the results by including additional fields in the initial search.
If you want to amend a key field (VRM, VIN, Agreement reference number), you will need to delete the original record and re-add using the appropriate options.