If you just came from a drive, give the engine about 30 minutes to cool down completely. One should not do any maintenance work when the engine is hot due to use, especially related to electrical equipments such as spark plugs.
Identify spark plug wires and grab one wire by its plug boot. If it can be pulled by bare hands, do it, else do not use excessive force trying to remove the wires. Instead use a spark plug wire puller to safely remove spark plug wires from their place.
Use an air blower to remove dirt and other debris around the spark plug. Use a socket wrench to remove one spark plug, remember you will have to rotate it counter clockwise in order to loosen it.
Use air blower to clean the inside of the spark plug compartment. Open the new spark plug box, take only one right now and replace it. Similarly open the new set of spark plug wires and replace the plug wire of the spark plug that you just installed.
Similarly follow this step for all other spark plugs remaining. Remember that you need to connect each spark plug with its own specific spark plug wire or it will cause the engine to misfire.
So remove one wire at a time and follow it to the distributor chamber and mark the slots 1 to 5 on the distributor cap. Usually there are 5 spark plugs in most car engines, however, depending on the make and model of your car they may be more than 5.
Most vehicles have little plastic pieces on top of the spark plug wires at their both ends which protects them from wear and tear. Make sure that the spark plug wires in your car are covered properly.