We have deliberately not made this a simple operation as the accession number is the objects unique identifier. There are two ways to approach this. Either create a collection called DELETED, then browse to the accession that you want to remove and change the collection to DELETED. Or, if you wish to re use the accession number. Ensure that you have the details of an alternate accession available. Then browse to the accession page that you want to remove and re write all of the inputs (except the accession number) with the next accession that you have prepared.