He clicked it.
In official Valve games, a "skin changer" usually refers to a cheat that swaps weapon textures without owning the skin. In CS 1.6, the term is more nuanced. Since CS 1.6 does not have a official skin economy, a is a tool or modification that allows you to replace the default weapon models ( .mdl files) with custom-made ones. CS 1.6 Skin Changer and View Model Changer