If the spray arms in your dishwasher are not dispensing water, then it is possible that your wash impeller is no longer functioning properly. It is important to remember that your dishwasher uses two impellers, the wash impeller and drain impeller. The drain impeller is accessed from the bottom of your dishwasher, but the wash impeller can be accessed from inside the tub, meaning there is no reason to drag out your built-in dishwasher. It will save you a lot of time to not confuse these two similar parts.
If you want to check the wash impeller, filter, or pump, all of which can cause your spray arms not to function properly, you can do all of that at the same time. In order to reach the impeller, it is a lot like disassembling Russian Nesting Dolls, and that takes you on a tour of many of the potential causes of this problem.
To start, remove the racks inside your dishwasher so you have access to the bottom spray arm. To remove this, there will either be a locking tab or a plastic nut that needs to be unthreaded. Once done, the spray arm will come right off.
Next, you will need to unthread the screws that hold the pump cover on and remove it. Now you need to remove the backwash arm and the filter. This is a great time to also clean the filter as well. Now you need to remove the screws that hold on the discharge cover, and under that, you finally have access to the impeller.
You can check the impeller for damage or clogs which can cause the spray arms not to function properly or simply replace it if you already have the replacement part. As you simply need to lift off one more cover, now is a great time to check the pump below that as well. The area can get dirty and clogged through regular use, so it wise to clean it now rather than have to come back and do it later.