Access the area where the tubes are located in the amplifier or receiver that is being used. Remove any screws holding the brace bar or protective grill for the tubes and set aside.
Remove the rectifier tube carefully. The tubes are most often right next to the large power transformer. The tube may be tight in the socket, so gently swirl the top of the tube to allow the pins to free themselves from the socket without damage to the tube itself.
Spray a very small amount of non-residue electronics cleaner into the socket. Allow it to dry.
Install the YJR adapter in the socket. Be careful to note where the pins are supposed to go.
Reattach any protective bars or bracing with the appropriate screws.