put them in your material library (a subdirectory along side your poses and characters and cameras etc) go into your material room in P5 and open your library. youll have a "materials" at the bottom (if it does not open automaticaly) it is only visable in your materials room. just select the materal zone you want to change and double click on the material you want to change it to (kinda like a MAT pose, only it will only change the currently selected zone)

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