CLEO3 setup was written once in time when no steam version is released. It checks if there's the file gta_sa.exe, while the steam's version has the one named gta-sa.exe. You can either temporarily rename this file before installing CLEO 3 and then rename it back, or install CLEO 3 from the rar archive version. http://cleo.li/files/cleo3.rar
How will i able to uninstall CLEO 3 After that?
Edit: The mod doesn't work when i press the respective buttons (Press 7)