Hello,
Here are the steps:
Convert Symantec Endpoint Protection clients from managed to unmanaged without uninstalling and reinstalling
1. Locate the Sylink.xml file that is located on SEP 12.1.4 Part1 in the SEP folder. (...Symantec_Endpoint_Protection_12.1.4_Part1_Installation_EN\SEP)
2. Copy the Sylink.xml file to a location that is accessible to clients on the network.
3. On the client, navigate to ...Symantec_Endpoint_Protection_12.1.4_Part2_Tools_EN\SylinkDrop.
4. Run SylinkDrop.exe on each Symantec Endpoint Protection client that needs to be converted to an unmanaged client.
OR
Check this Article:
How to change managed Symantec Endpoint Protection(SEP) client to unmanaged SEP client?
http://www.symantec.com/docs/HOWTO36107
NOTE: The article is created for SEP 11.x, however would work for SEP 12.1 upon disabling the tamper protection.
Hope that helps!!