The previous installation of Sybase CEP Engine is automatically removed if you are upgrading to a new version.
Sybase particularly recommends backing up the following information before proceeding with the upgrade or reinstall:
Any customized files in your Server\conf folder.
Any information in your adapters base folder (by default the adapters base folder is named SybaseCEPRepository).
Any custom adapter .adl files.
Any user-defined function .udf files.
Any custom library .so or .dll files.
Even if you are upgrading or reinstalling to a different directory, Sybase recommends that you back up your adapter base folder as a precautionary measure before proceeding.