while this is a open disscusion again ill go ahead and tell you all how to open DTX files in photoshop.. or any other software, USE DEdit preferably, import textures (DTX) export textures (TGA) once its (TGA) it should open easily still if not, the veeeery best thing you can do is get a screenshot tool, outline the DTX file and screenshot it, save it as a jpeg. From there you can open the screenshot in photoshop, edit it, once you edit it save as original file ''replace the existing file such as PV_G36E .. and your done..