Now that you have a 9V adapter for your walkie talkie, you need a way to get power to it. The easiest way to do this is to add an AC outlet plug to the TV's power cord inside the housing.
Follow the power cord from where it enters the TV to the place where it is soldered to the main circuit board. Cut the cord at the midpoint of this section. On each side, separate the two wires by cutting the insulation between them and peeling them apart. Then strip about 1/2 inch of insulation off each end. This will give you four bare ends.
Take a second power cord and cut a few inches from the female end. Then again separate the two wires and strip 1/2 inch of insulation off the end. Now match up the bare ends of these wires with the others so that one side of each cord is grouped together as shown in the picture. You should now have two groups of three wires each. Connect each group together with twist-on wire connectors. Make sure that all bare wire is properly covered by the connector caps. This will have reconnected the TV's power cord and with a female plug added in the middle. You can use this to plug in your power supply and continuously power the walkie talkie as long as the TV is plugged in.