We recently decided it was time to install a new dishwasher in our kitchen. This is the second one we’ve put in (we replaced the one on our old house too) and the process was pretty similar in both cases.
Here’s a copy of the installation instructions for the Bosch SHX43M0xUC dishwasher we just installed. We wound up making a few modifications to the process because of the location of our electrical and water supply lines. Here are the steps we followed in case anyone else finds them useful:
Removing the Old Dishwasher
Remove the kick plate panel by first removing the screws connecting it to the dishwasher.

Removing the kick plate
Flip the breaker for the dishwasher and verify that there is no power going to it. This took several tries for us … we had two breakers labeled “Dishwasher” and neither of them actually powered the dishwasher.

Locating the breaker for the dishwasher
Disconnect the electrical from the dishwasher by removing the junction box cover, removing the wire nuts connecting the hot and neutral wires to the dishwasher, and disconnecting the ground. Then loosen and remove the strain relief connecting the electrical wire to the strain relief plate and feed the wire through the strain relief plate to completely disconnect it from the dishwasher.

Unhooking the electrical connection
Locate the shut-off valve for the supply line and turn off the water supply.

The shut-off valve for the hot water supply
Disconnect the supply line from the dishwasher. In our case, we had trouble loosening this connection from the old dishwasher, so we chose to disconnect the supply line from the copper pipe in the basement and feed it up through the floor in order to remove the dishwasher. We were then able to remove the braided supply line from the dishwasher after it was pulled out from between the cabinets.

Detaching the supply line
Disconnect the drain hose. It’s a good idea to have a bucket handy for this part to catch any water still in the drain hose.

Detatching the drain connection
Remove the screws from the brackets attaching the dishwasher to the counter top.

Remove the Screws Connecting the Dishwasher to the Counter
Adjust the leveling feet and slide the dishwasher out from the opening in the cabinets, being careful not to scratch the floor. We found it useful to use the cardboard from the new dishwasher for sliding the old (and new) dishwashers in to and out from between the cabinets.

Removing the Dishwasher
Installing the New Dishwasher
Unpack the new dishwasher and remove the kick plate panel. It was so cold when ours arrived that the inside was covered in frost.

Unpacking the new dishwasher
Adjust the front leveling feet to the approximate height needed for the installation and connect the drain tube to the back of the dishwasher.

Adjusting the leveling feet
Test fit the dishwasher in the opening to verify that the electrical and water supply line connections can be made. When sliding the dishwasher into place, feed the drain tube into the cabinet under the sink, leaving any extra tubing coiled behind the dishwasher. If necessary, mark the location of new holes to be drilled for running the water and electrical lines to the dishwasher. Slide the dishwasher out and drill the new holes. Then put the dishwasher back in place.

Relocating the electrical and water supply lines in the basement
Make the electrical connection by connecting the strain relief to the strain relief plate, feeding the electrical wire through it, and clamping it tight so that the electrical wire is held in place. Then, connect the hot, neutral, and ground wires to the dishwasher and replace the junction box cover.

Making the Electrical Connection
Connect the hot water supply line by attaching a 90-degree elbow joint to the dishwasher using thread seal tape and then connecting the braided supply line to the elbow joint.

Connecting the Hot Water Supply Line
Connect the drain tube to the drain under the kitchen sink. Our set-up is a little different than the typical arrangement where the dishwasher drains through the garbage disposal or kitchen sink drain, but the idea is the same.

Connecting the Drain
Finish leveling the dishwasher and attach it to the counter. Our dishwasher had a screw in front for adjusting the back leveling leg which made the process of leveling it much easier.

Attaching to the Counter Top
Restore power and water to the dishwasher and check for leaks by starting a cycle and then canceling it so that the dishwasher fills and then drains.
Install the kick plate by screwing it in place.

The Newly-Installed Dishwasher