I am in the cleaning a large amount of mineral deposits from my dishwasher. i have disassembled to the wash impeller, which I broke in try to remove it. I have a new part on order but in themean time I need to remove the remainder of hte impeller and finish removing the deposits. how does the impeller come off? Does it screw off? maybe mine is stuck from all the build up. Help! I've tried finding a manual online with no luck.

Thanks to anyone that can help me!