Set the max carry weight you want via menu option while playing.
Load a save go to: Main Menu -> Options -> Game -> Max Carry Weight
Select the max weight you want and hit apply.
Available max carry weight selections:
S.T.A.L.K.E.R CoC 1.4.22
S.T.A.L.K.E.R CoC 1.5 R6
Extract "gamedata" directory from archive to your S.T.A.L.K.E.R CoC directory.
Should be compatible with any other addon.
Does not edit or replace any CoC files at all.
Updated Russian translation thanks to av661194.
Added a few more max carry weight selections.
Minor version check change.