EZSkin 3 will not work in Poser 12 so forget that route for the moment until there is an update available. EZSkin 2 might work in P10 but I don't have that version installed on my computer anymore. And even if you were able to create earlier EZSkin shaders there is no guarantee that those will work in P12. The alternative to V4 Skin textures is to either change the chip on the diffuse color to white and it must be done for each Material Zone, or recreate new skin shaders by editing the nodes or starting from scratch. ATM, there isn't any easy way to do bulk changes to model skin shaders. Keep in mind, the changes that were done in the Material Room in P11/P12 will detect bad node connections and will inactive those features when rendering.