You can very easily replace your normal light switch on the wall with a dimmer switch. The first step is to turn the power off at the circuit breaker. To prevent anyone from accidentally turning the circuit on put a piece of tape over the fuse switch so that it is clear that it is to stay turned off. Remove the screws that hold the switch plate and use a tester to make sure that none of the wires are still live with electricity. Remove the two screws that are holding the switch itself in place and pull the switch out of the box in the wall. Loosen the screws and take the wires off the screws or take them out of the back of the switch if they are wired into the back. If the wires are bent cut them off and strip the insulation off of the wires. Twist the wires coming out of the wall with the wires coming out of the dimmer. Put a wire nut on the twisted wires and push the wires back into the box. Line the switch up and screw it back into the wall. Put the switch plate back on the wall and you are all finished.