Steps for translating text on image files:
1) Translate the text in the TGA files
2) Convert the translated TGA files into GIF files using a third party image editing tool. 
3) Run Convert_All.BAT to convert all GIF files into the game's proprietary image file format. 
4) Copy all the files generated by Convert_All.BAT, including *.ICN and *.COL to the game's IF folder (<Capitalism Lab folder>/IF).