Turn off your Villager's engine, engage its emergency break and remove the keys from the ignition. Make sure the headlamp switch is set to "OFF".
Open the liftgate and look for the two screws that hold the taillight assembly in place. Remove the two screws and place them in your pocket or somewhere else safe.
Remove the assembly from the rear pillar by pulling it backward. Be careful not to scratch your Villager's exterior paint.
Find the socket holding the bulb you want to replace. Turn the socket counter-clockwise and pull it out of the assembly.
Pull the broken bulb directly out of the socket, and then replace it with the new bulb.
Screw the bulb socket back into the taillight assembly. Place the assembly back into its original position and start the van's engine.
Test the new bulb to make sure it works. If it functions properly, screw the assembly back into position and close the liftgate.