I had a shut off water supply shut off shut under my sink. That is where I shut the water off for the dishwasher. I knew it was for the dishwasher ,because it follow the line, and could see it was going to the washer. Then I went down stairs in the basement. Opened my breaker box, and found the breaker for the dish washer marked dish wash
... Read moreer, and put in the off position. When I was still up stairs I opened dish washer , and inside at the top was two screws holding the dishwasher to the counter top. Those two screws turned out to be the exact size of just about every screw I ended up having to unscrew on this machine. So at the time I was in the basement turning off breaker, I went to the garage to gather up tools. Take the two screws that are screwed to the counter top. Then I layed on the floor, and at the bottom of the dish washer there is a panel on the front of the machine with screws attaching it. Take those screws out. Pull off cover. Now get a flash light so you can see. They're adjustable feet that the dishwasher are being leveled by. Those feet need to most likely be adjusted down so you can the machine pulled out, and make it possible to work on. now you can you can pull it out, but watch that water supply line does not get hung up, or electrical wires. Once the machine is pulled out there is another cover on the front that I took off. Four screws hold it on. Now you can get to the part to fix it. The other thing you need to know is after taking off the valve and taking off the old 90 fitting. It will need cleaned up. When you put it on the new shut off valve use pipe dope or thread tape so it doesn't leak. Good luck.