If you are planning on fitting parts to your car your self you have to be fully confident and know exactly what you are doing through out the job. With parts that will need to be changed more regularly its thought you should learn how to change these first. For example spark plugs are thought best to be changed every 30,000 miles to keep them in working order. Here are some simple instructions to follow on how to change your spark plugs:

1. Pull the hood up with the release lever which is located under the dashboard usually.
2. Go to the front of the car, reach under the hood, find the latch and squeeze it to open the hood.
3. Find the spark plugs, they will be down one side of the engine (on an in-line four-cylinder engine) and they will be attached to thick wires, called spark plug wires. V-shaped engine models of cars (which can have four, six or eight cylinders) will have spark plugs and spark plug wires along both sides of the engine.
4. It’s important for you to change one spark plug at a time, always putting the spark plug wire back on before changing the next spark plug, for details of what can go wrong read on.
5. Pull off one spark plug wire where it attaches to the plug. There is a little rubber section at the end of the wire with the plug; pull on this part. With the wire being quite fragile pulling higher up on the wire can damage it and if damaged it can come apart.
6. Wipe or blow away any dirt or debris around the spark plug ends. You do not want anything to get into the cylinder while the spark plug is out.
7. With the spark plug socket and a ratchet, remove the spark plug by turning it in a counterclockwise direction. You may need an extension section for your ratchet if the spark plugs are deep-set or not directly accessible. It is very helpful to have ratchets with flexible heads if the plugs are not easily accessible.
8. Check the spark plug once removed to make sure it actually needs replacing. A good spark plug should be lightly coated with slightly grey and brown color. You will be able to tell it needs changing if it has heavy deposits, if the spark plug is black or if either of the electrode or core nose are damaged, the plug needs to be replaced.

You could get a lot more advice on changing larger parts of your vehicle either in specialized courses, on line or if you go into a local parts garage.