Well then just download the current
zip from the github page.
Unzip in windows/OSX/Linux.
Copy to your Synology.
Put it in the web folder (name the unzipped COPS folder COPSnew)
Copy the config_local.php file from the existing COPS to COPSnew or edit the relevand values in a new config_local.php file in COPSnew.
... and try it out!!! (99% it will work, if not, just delete COPSnew)