Diagnose diswasher problem?

I have kenmore 63016303401. there is not enough water pressure to clean the dishes.
water does get into bottom. enough to cover the filter screen. If I open the door I just see a little water coming out of the spray nozzle. also the rinse cycle stays at 1 minute for over 40 minutes. If I hit cancel the water does empty out.
how do I tell if enough water is in the machine?
would a bad circulation pump cause the rinse cycle not to end?
how do you remove the metal sides so you can remove the lower end?