Disconnect the lamp fixture wires from the circuit wires. If the wire joint is fused together with old insulating tape, cut the wires close to tape. Caution: If wires or insulation coming into electrical box are brittle or frayed, that part of circuit should be professionally rewired. Once you remove the old fixture, examine the electrical box and the new fixture to determine which of the following installation procedures you should use for additional steps.
For fixture installation in standard electrical box:
Make sure you have about 3/4 inch of bare copper conductor on the end of each line wire before you start to connect the wires of your new lighting fixture. If necessary, remove enough insulation from the line wires so you can twist each line wire end together with the end of each light fixture wire, white wire to white wire and black to black. Screw the wirenut tightly over each pair of twisted ends. Hold onto the fixture to support its weight until you attach the mounting screws; otherwise, you might break a connection or damage the fixture wires.
If fixture has more than one socket:
Connect the black wire from each socket to the black line wire and the white wire from each socket to the white line wire. When three or four socket wires are joined to the line, use the larger wirenut.