Pump not discharging water, problem with lime deposits.
How do you remove lower spray arm?
If the wash pump is stuck due to hard water deposits, you have to install a new impeller & seal kit.
If the dishwasher is not draining - it could be a clog in the drain line or a bad drain pump.
To remove the lower spray arm - just pull it up.
So what is exactly wrong with your dishwasher?
Here are the break down diagrams for the GE dishwasher Model GSD6200G00BB
Gene.