The first thing to remember is to wait for your engine to cool off. You may want to wait at least a day after running your car.
Your next step is to disconnect the negative battery cable. After doing this make sure any obstructions to the timing belt cover are out of the way. This may take a bit of time and may include air intake assembly, the water pump pulley and other accessories. Each car is different and will have different things that may interfere.
You may want to check a repair manual for your car’s particular model to see if your car has a distributor cap. If it doesn’t have one, then it should tell you what to do from there. This may be as simple as making sure the cam position sensor is set to TDC. Otherwise, just remove the distributor cap.
Next, using a wrench on the bolt of the crankshaft, rotate the engine until the timing mark on the pulley is lined up with the “0” mark on the timing scale. Then remove the timing belt cover. Check the timing belt tensioner bearings and replace them if they are loose. Move the tensioner away from the belt. You can then slide the timing belt off to remove it.
After this, put the new belt in place and adjust the tension as necessary. Be sure it fits properly over the teeth of the timing sprockets, but don’t make it too snug.
The next steps are fairly simple: apply a new gasket onto the timing belt cover, reinstall all of the items you previously disconnected, reconnect the battery and start the engine to see how it runs. If it knocks, you may have missed something. If it doesn’t, then you have successfully changed the belt.