Problem with a mod of the Suika Game Thread

First of all, sorry if my English isn't pretty good, xd.

I picked the QS-Studio version of the suika/watermelon game, witch is made on unity. I used two programs, the Asset Studio and the UABE(Unity asset bundle extractor).

The problem was when I try to open the file named data.unity3d, witch contains all the assets, with the UABE, that returns an error. So I had decompress the file with the asset studio, and modify the file witch contains the images. But now the issue, is that is imposible to compress it again, and the game doesn't work with this file decompressed.

Does anyone have a suggestion? Ask me for any more info that you need.