Removing a 4-prong electric dryer cord when replacing it with a 3-prong electric dryer cord is easy when you follow these directions. First, disconnect the black wire, one of the "hot" connections, from the left side post by removing the terminal screw. This is one-half of the 240-volt connection.
Next, disconnect the red wire, another of the "hot" connections, from the right side post by removing the terminal screw. This is the other half of the 240-volt connection.
Then, disconnect the white wire from the center connection. It is used for the neutral connection.
Now, disconnect the green wire from the machine case by unscrewing the green screw.
The next step is critical to return your electrical connection to factory condition before installng the 3-prong cord! Locate the white machine wire that is now connected to the neutral (center) screw terminal. Disconnect it from there and install it under the green ground screw.