Piece of cake. My Dad tried and could never get his on, but he's an impatient SOB and gives up easily. The first time I ever put one on, it took about 30 minutes, but ever since then I've been able to get even the new one for the SuperTop hardware on in about 10 minutes or so.
jwrape - Are you sure you have the right top? If you have an OE top, there is a different Duster than if you have a SuperTop or something else.