HELP HOTPOINT dishwasher wash arm wont turn!

[maytaga806]

This is a little tiny wash arm on the top of my VERY old Hotpoint Potwasher dishwasher with water temp boost. It just sits there and shoots very little water out. How do i take it off with out breaking it to clean it?? there is only 2 tiny holes on it. Its a dark picture but i will post another one. HELP!!

 

[appnut]

Initially I wouldn't touch it.  Clean out the entire dishwasher with what has ben suggeswted to you.  There has got to be scale build-up through the entire water circulation system and tha twould include the 3rd little wash arm and the piping leading uip to it.

 

[maytaga806]

thanks for the feed back!!!