Server Configuration > Service Packs and HotFixes > Rolling Back Server-side Service Packs > What You Need
  
What You Need
The rollback uses a rollback ZIP archive to perform the changes. Ensure that the archive ZIP exists before attempting to perform the rollback. The archive is located in the following location:
installdir/server/mks/patchrollback/servicepackrollbackservicepackID.zip
where installdir is the path to the directory where you installed the Windchill RV&S server, and servicepackID is the ID number of the service pack you are rolling back, for example, servicepackrollback010000001-01.zip.