How to change the name of a material parameter?

Hello, I have been working on a character creation system using VROID and Assembly plugin from the marketplace. According to the material parameters, mtoon_ShadeColor is what dictates a major color change for at least 3 different materials (eye iris, eye white, and a portion of the hair material). According to the Assembly plugin creator, the only way to accomplish differentiating this is to change the name of the material parameter. When I try to change the name of the parameter it disappears or breaks the material(and ue4 crashes). Regardless it does not change so that I would be able to manipulate each parameter separately. Does anyone know how I can accomplish changing the name of a material parameter?