Turn off the power to your foyer at the main electrical panel.
Remove the old light fixture. Depending on the style of the existing light fixture, you may need to remove the glass dome or globe to unscrew the base. Remove the screws securing the fixture to the crossbar in the electrical box and lower the fixture. Do not disconnect the fixture until you complete the power is turned off.
Ensure that the power to the foyer is turned off by testing the wires. Turn the wall light switch on and move the tip of your non-contact voltage detector near the wires. If your tester lights up and indicates that electricity is still reaching the wires, go back and flip the correct switch in your electrical box. Unscrew the correct fuse if you have an older electrical system with fuses.
Disconnect the wires from the existing light fixture and leave the other wires tucked up in the electrical box. Set the old light fixture aside.
Turn the power back on at the circuit breaker box. Test the red or colored wire with your non-contact voltage tester. It should be "hot," meaning that your tester should light up. The wall switch should still be on at this point.
Use the neon voltage tester by touch the leads of this tool between the hot wire and the metal electrical box, or between the hot wire and uninsulated copper ground wire. You can proceed if the tester lights up, indicating that the metal box or bare copper wire is grounded. If the tester doesn't light, call a licensed electrician to supply a ground.
Turn off the power to the foyer once again before continuing. Turn off the wall switch.
Preassemble any parts of your new light fixture, if necessary. Adjust the length of the chain for hanging fixtures.
Align the new fixture's crossbar with the electrical box and move all of the wires to one side of the crossbar. Screw the crossbar to the electrical box. You may need someone to help hold the fixture while you perform this task.
Test to make sure that none of the wires in the box are hot. Reconnect the wires to your new fixture. Screw on the wire connectors that were provided with your new fixture to complete the connection.
Install the canopy or base of your new light fixture. Add the bulbs. Add the glass globes or shades to complete the assembly of your fixture.
Turn the power back on and flip on the light switch to check your work.