You have successfully upgraded your Enforce and Endpoint servers using the Upgrade Wizard via the Enforce interface console and would like to upgrade your Endpoint Agents.
Data Loss Prevention 15.8
The Upgrade Wizard used to upgrade the Data Loss Prevention (DLP) servers does not provide a facility to remotely deploy the upgrade package to Endpoint Agents.
For details on each option please read your Upgrade Guide.
Useful references:
Is it possible to apply an agent configuration to one endpoint agent?
Is a reboot necessary after upgrading the Endpoint Agent?
related-documents-15-8
Note: Follow the upgrade guide for the above link i.e. Symantec™ Data Loss Prevention Upgrade Guide for Windows/Linux as per your environment, Version 15.8