Modding the graphic assets

Hey,

pretty new to the game and especially new to this community, so sorry if this is a totally retarded question. I could not find any thread that covered this topic on the first page, and I could not be arsed to look through all of the pages.

But, is it at all possible to modify the 3D-assets and/or textures of the game? I would very much like to rework some of the assets.