WCIF a tutorial for Deco Sculpture --> Toy Conversion?

I have no idea how to use Blender (or make CC at all aside from recoloring stuff in Photoshop and doing basic tuning adjustments), so hopefully this won't be too complex... I tried just cloning another CC toy item and importing the new texture and mesh that I wanted onto it. And it sort of works, but in the game it'll periodically flip back to the old mesh with the new texture, both when the kid's playing with it and when it's just sitting undisturbed. So I'm sure there's something I'm missing, but I'm not sure what.

Any help appreciated!