ZBrushCentral

New here

I already posted this but i think i accidentally posted it in the wrong subforum, anyway i am new to Zbrush, having been using 3ds max for some time (self taught so my skill is spotty at best). I have a 3d model i want to 3d print. It is from a game “Supreme Commander”. THe thing is that the model is rather simplistic and most of the “geometry” is handled by texture. I broke up the model into smaller chunks to be easier to work with. First thing i want to do is a foot:
foot.jpg

If you can see those dark lines, that is a texture. I want to make it 3 dimensional, i already imported the model with a texture into Zbrush, how do i go about modelling this?