In the replacement before the electrical outlet to break off, if not find the socket in which line on the first circuit switch off. When you turn it off, you can start it, and you need to remove it before you change it.
The screws in the wall socket are inside, and the outer cover plate is pried down to see, and a screwdriver with a flat mouth can be pried off lightly by one side. When you're done you can see the screws and twist the screws down.
Unscrew the screws will be able to remove the socket from the wall, the internal generally connected with three lines, respectively, the FireWire, 0 lines and ground, the line can be removed to replace the other sockets.