Contacts can be exported from the Contact page in Karbon by selecting the cloud icon, then select the data you would like to export. A spreadsheet will then be downloaded with your data.
If you are planning on manipulating this data to upload back to Karbon, keep in mind that if the names are changed, duplicate entries will be created. Changes to names should be made directly in Karbon. Other changes, such as contact type, address, phone numbers, etc, can be made in the spreadsheet.
If you see duplicate individuals, this may be due to that person having multiple contact cards in Karbon. If the "duplicate" contacts have the same key in column one, then they are not duplicates, just multiple contact cards.