Things You'll Need
Instructions
Load "GCFScape," click "File" and select "Load" to immediately go to your "GMod" installation directory. Double-click the file "materials.gcf" to open it in "GCFScape."
Once the "materials.gcf" file is open, browse through the file directory to find model materials, such as male, female or different race models. Select a model type you would like to edit.
Right-click the skin file and select "Extract" to place the file into a different location outside the "materials.gcf" file. Load the skin file with your photo editing program.
Apply alterations to the skin using the coloring tools and shading options available to you. Apply the cutting tool to remove clothing options and replace with your own style, if you so desire.
Save the skin file and close the editor. In "GCFScape," drag the new skin file into the same directory you got it from. Accept the prompt to replace the original file.
Close "GCFScape" and load "GMod" to test your new skin.