Just remove the monitor driver from Devs:Monitors. That will deactivate it and P96 should install and work happily.
To get rid of it completely, there are one or two cgx#? files in Libs:, along with CGXMode in Prefs, the CyberGraphX commodity (also usually in Prefs), some ENV vars in ENVARC:, showcgxconfig in Tools, and some Help files somewhere in HELP:. I think that's all.
