Open the dishwasher door and remove the old tub seal. To remove the tub seal, grasp the end of the seal, which is at the bottom of the tub opening, and pull it away from the appliance. As you pull, the seal pulls out of the gasket channel. Continue pulling until the seal is completely removed.
Place the new tub seal in a tub of hot water for about five minutes. Soaking the seal softens the rubber, making it easier to insert into the tub channel.
Remove the tub seal from the water bath, and then locate the center of the seal. On many seals, there is a red or pink dot on the seal itself, indicating the center.
Position the seal so that the center of the seal is aligned with the door latch.
Press the tub seal into the seal channel using your fingers. Move down the tub seal, inch by inch, pressing it firmly into the seal channel until one side is completely inserted in the dishwasher's seal channel. Repeat for the other side until the seal is fully installed.
Close and latch the dishwasher door. Latching the dishwasher door forces the seal to mold to the channel, which lessens the likelihood of the seal coming out of the channel. Allow the door to remain latched for several hours, preferably overnight, to ensure that the seal has time to be properly molded.