Deduplicate and tidy 5600 rows in a sales database

We have an excel spreadsheet of sales leads, which have been exported from a CRM. Unfortunately the sheet contains duplicates, which we would like to remove, whilst preserving the most data.\r\n\r\nThe spreadsheet has ~5600 rows, with approximately ~1500 duplicates, with 15 columns.\r\n\r\nAs an example, a duplicate row might be:\r\n\r\nName, Email, Phone 1, Phone 2, Address, Notes\r\nJon Smith, email1, -, -, 50 Portland Street, -\r\nJon Smith, - , -, 020 1234 1234, -, -, 60 Edgeware Road, -\r\nJon Smith, email2, -, 07930123123, -, -\r\n\r\nWhat we want is:\r\nJon Smith, email1, 020 1234 1234, 07930123123, 50 Portland Street, Other Address: 60 Edgeware Road, Other email: email2\r\n\r\nThis way, all the information is preserved in a single row, with the differing data preserved in the Notes field.\r\n\r\nThe columns in the sheet are:\r\n\r\nOpportunity Owner\r\nFirst Name\r\nLast Name\r\nTitle\r\nCompany / Account\r\nLead Source\r\nRating\r\nTelephone 1\r\nTelephone 2\r\nEmail\r\nWebsite\r\nAddress\r\nNotes\r\nData Source\r\nData Age\r\n\r\nI\'d estimate that this is around 2 to 3 hours work.