Upper wash arm worn out

This was extremely easy!

First, I removed the small plastic retainer' from the upper wash arm assemby by pushing it up with my finger and grasping the retainer with my other hand, I removed it from the assembly. I then placed the new plastic retainer into position with my left hand and pushed the upper spray arm against the bottom of the assembly and snapped on. Since all of the parts are plastic, the upper arm sprayer simply snaps into place!