Help to repack a game

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Hello all. I just joined fileforums and don't know much about repacking. I repacked a software (Adobe photoshop CS6 extended edition) to 215MB from 1.28Gb now want to repack games. I wanted to start with a small game (this war of mine, 754MB) first but faced failure in the first step. my repacked size was only 20MB lesser than the original. I am putting images (see the attachment) of the files included in the Game folder so that you can understand which method will work best for them? plz help anyone. in one day I have searched almost all tutorials here in fileforums and have got some basic idea about compression. but still need help. plz help Sirs