Open your dishwasher door. You do not need to turn off the electrical power to your dishwasher in order to remove the tine rows.
Pull out the top rack containing the tine row you want to remove. Locate the tine part that needs replaced, and find the four clips connecting the tines to the rack.
Unsnap the clip off the rack bars by pulling up on it, and then unsnap any other clips that remain on the tine you want to remove.
Pull the first tine out and remove the clips from the second tine. Pull the second tine out and the row will be removed.
Insert a tine part into the connectors attached to the rack, and then snap all of the clips back onto the tines.
Slide the top rack back into the dishwasher. Close the door.