when you create 3D Object and expand it, then ungroup the shapes, it still has the mask shape, so you do release clipping mask, it will release the mask with keep selecting this mask, so hit delete on the keyboard and all done! :).

“Expand 3D object and clean the shapes. Select the object and click on the Object>>Expand Appearance from the menu, then right click select Ungroup right click again select Release Clipping mask then delete the mask *note that the mask appear without stroke and fill color. then select the shape and right click again ungroup .”

I get to here, then i get stuck…then delete the mask – where do i delete the mask? Sorry, a little new 🙂