Okay, here are the photos. This is of a Design Spot 575E, so no static wheel. The rotating wheel should be the same however (I am pretty sure that the whole assembly is shared between the DS 250, 300, 575, and 1200, only the 1400s have a different one).
First up is a semi-wide of the fixture with the cover off. You can see the one gobo wheel (Other is accessible from the other side) and the color wheel behind it.
Next is how you have to pop the wheel out, notice the little tiny screws that catch and help hold it in the assembly.
A shot with the wheel fully out. You can see the clamp at the bottom which holds the wheel in place from the bottom.
Front side of the holder. The catch is on the bottom.
And finally, the outside of the holder. You can see the spring which holds the gobo in place and the little screws that help hold it into the assembly.