How to go from this
I'm pressumming you know how to work with layers and that you have Photoshop.
DOWNLOAD BLENDER BRUSH HERE
Download the Blender brush.
Place the BLENDER.abr into the following folder
C:/Program Files/Adobe/Adobe Photoshop CS3/Presets/Brushes
Open Photoshop and the brush should be present under your brushes and called BLENDER.
Should work perfectly fine for CS2 versions of Photoshop also.