Instalation for 2.7x

Customization for matcap is not available in Blender 2.7x. However prior to matcap shading even being available in Blender it was possible to use setup similar to matcap inside Bender Internal engine. The way you can do this is by making material that has matcap texture and coordinate of that texture set to normal. Preferably material is set to be shadeless.

These material setups are available in source file if you chose to purchase them.

Installation for 2.8(experimental)

 If you want to use these matcap images with Blender 2.8 experimental which is available now you need to:

• Download experimental build from Blender website.
• Extract Blender files and navigate to Blender settings folder:

[path to blender instalation folder]/2.80/datafiles/studiolights/matcap/

Unzip MATCAP file inside this folder and images will be available in shader popover.