If you used the installer, then it came with an uninstaller file that you can simply double click. IIRC, the uninstaller is in your "Taldren Software Inc / Starfleet Command" folder.
Should return you to 2552 and OP+ 3.3 set-up.
Edit: I made some assumptions that you are use to playing around in Window's "Explore" (right click Start button, then select Explore to open). If I'm wrong, just say so. Someone will provide a walk through (I'll make sure to check back before logging off for the night).