Lower Spray Arm with Tower WD22X155

Apply large vice like pliers at base of the lower spray arm and not applying too much pressure to plier as this is an all plastic part and slowly turn counter-clockwise until entire spray arm is loose enough to lift out and install the new part in the reverse order.

The lower spray arm unscrews. From inside the dishwahser, put a screwdriver through the tab slots and unscrew the tower from the floor. It's pretty tight for plastic.
The upper spray arm has screws on the top of the dishwasher. You must slide the dishwasher out from underneath the countertop to get to the screws. Normally that's just the two screws above the door that screw into the countertop. Pull the insulation back and unscrew the arm from the top of the dishwasher. Reverse to reinstall.
Piston and nut assembly for check valve: Inside the dishwasher at the back there are 2 screws that hold a screen down. Remove the screen. Take out the check valve and replace it. It was still functional in mine, it looked like food gunk had built up on it and impeded the check valve action.
The flapper chec is a rubber flap in the drain tube that connects to your sink drain. You have to pull the dishwasher out from under the sink to get to the end of the drain tube that connects to the dishwasher. Take the hose clamp loose and remove the drain tube from the dishwasher. Then unscrew the plastic fitting that you just took the drain tube off of. The flapper chec is there. It had turned brittle and didn't flap anymore. It is a similar setup to the rubber seal at the end of your garden hose.

turn wand counter clockwise until it's out,replace it with the new one.DON'T OVERTIGHTEN!

i removed the old power tower with a regular plumbers pliers spining SLOWLY and firmly but no too firm until it broke loose and unscrewed. I reintalled the new tower oppisite how i removed it being carefull not to overtighten. all is well. it was very ez, so much in fact that my wife thought she was going to be able to read a book waiting for me "all afternoon" to fix it! Bad news, I had to take her shopping!

i was impressed with the ease and speed of normal delivery of this part. this is a quality company. JS

I removed the broken lower spray arm tower using a scew driver and snapped in the replacement part not needing any tools.

we took the surrounding cover off the machine, then took out the bottom basket. turned the dishwasher on it's back for easy access. open the door and unscrew the lower spray arm from the rubber connector, then loosen the clamp around the connector and pry out. the connector is a little hard to put back on because of the need to be tight but a little muscle does the trick! then screw the new spray arm back onto the connector from inside the machine making sure you get it tight, without using a tool on it. then just re-attach the cover.

with a pair of pvc pipe pliers,I loosened the Spray arm and replaced with the new one.Soap residue had built up inside and would come out on the clean dishes due to a worn plunger from an earlier repair.Also fixed the dryer start switch in 5 min thanks to the info from this site.

Getting the upper part of the lower arm out was easy. It is just tabs that hold it in. Screwing the old one out was the hardest part it was fused in with dried detergant but once it was loose it was a real easy to put the new one back in.