You can use the Denodo [Predefined stored procedures](https://community.denodo.com/docs/html/browse/latest/en/vdp/vql/stored_procedures/predefined_stored_procedures/predefined_stored_procedures#predefined-stored-procedures) like GET_ELEMENTS, GET_VIEW_COLUMNS, etc. to figure out if there are any difference in elements across Denodo 7 and 8. At the moment, there is no automated method available to export and import only the elements modified.
To modify the classpath of a few sources, you could use the ALTER DATASOURCE command to manually update the latest driver class path in Denodo 8.0. For more information, take a look at the [JDBC Data Sources](https://community.denodo.com/docs/html/browse/8.0/en/vdp/vql/generating_wrappers_and_data_sources/creating_data_sources/jdbc_data_sources#jdbc-data-sources) section of the Virtual DataPort VQL Guide.
Starting from Denodo Platform 8.0, the approach is slightly different. For using other JDBC driver, you need to import the jar using the [Extension Management](https://community.denodo.com/docs/html/browse/8.0/en/vdp/administration/importing_extensions/importing_extensions#importing-extensions) option of the Virtual DataPort Administration Tool or via VQL and then use it.
Also, for the keytab files, now you need to get the keytab file in your local machine and it need to be uploaded to the server which will be placed in an internal location. For more information, take a look at the [Setting-up Kerberos Authentication](https://community.denodo.com/docs/html/browse/8.0/en/platform/installation/postinstallation_tasks/postinstallation_tasks_in_virtual_dataport/setting-up_kerberos_authentication#setting-up-kerberos-authentication) section of the Virtual DataPort Administration Guide.
Additionally, if you face any issues and if you are a user with valid support access then you can create a support case in [Denodo Support Site](https://support.denodo.com/) so that our support team will assist you further.
Hope this helps!