Removing bottom wash assembly

I am trying to remove the bottom wash (sprayer) assembly, there is what looks like a plastic retainer screw in the middle of the assembly. It seems to be stuck (or?). Does anyone know how to remove this assembly?

This is a duplicated thread.

Answered here: http://forum.appliancepartspros.com/dishwasher-repair/44058-trying-remove-kitchen-aid-wash-assembly.html

Gene.

[QUOTE=Gene;117290]This is a duplicated thread.

Answered here: http://forum.appliancepartspros.com/dishwasher-repair/44058-trying-remove-kitchen-aid-wash-assembly.html

Gene.[/QUOTE]
What is a duplicated thread?