Put all files inside a clean Zero Hour directory (with no mods installed) and rename Scripts folder to Scripts1 (which is located inside Data folder).
Only one of these files must be inside your Zero Hour directory:
"!Contra008Beta2RU.big" - for Russian language.
"!Contra008Beta2EN.big" - for English language.


If you see strings like "MISSING:bla-bla-bla" instead of names and descriptions and/or purple rectangles instead of buttons and unit icons, here's the fix:
Extract !Contra008Beta2.big and !Contra008Beta2EN.big with FinalBig in a new folder named with the language of your game (German, French, etc.).
This new folder must be in the same folder where you installed Contra.