To play the mod you need to have been installed in Steam Half-Life 2 with Source SDK Base 2007. Then download "cstrike_classic.rar" archive in provided above link. Once it finished downloading, extract it to your "sourcemods" directory, for example "C:\Program Files (x86)\Steam\steamapps\sourcemods". Then change language in Steam to English. Quit and restart Steam. Then in library you will see "Counter-Strike: Source Edition". Left-click on "PLAY" button.