Changing the petrol filter is a relatively easy process that can be done by following these steps:

1. Locate the petrol filter. It is usually found under the car, near the fuel tank or close to the engine.

2. First, relieve the fuel pressure by using the fuel pump relay or by disconnecting the fuel pump fuse or battery. This will prevent fuel from spraying out, causing a hazard.

3. Use a wrench or pliers to disconnect the fuel lines on both ends of the filter. Make sure to catch any fuel that spills.

4. Remove the old petrol filter by unscrewing the filter housing.

5. Insert the new petrol filter into the housing, making sure the flow direction matches the arrow or markings on the filter.

6. Tighten the filter housing and reconnect the fuel lines in the correct orientation.

7. Turn on the ignition to prime the fuel system, then check for any fuel leaks.

8. Test drive the vehicle to ensure everything is functioning normally.

It is important to note that changing the petrol filter regularly is important as it helps to keep the fuel system clean and prevent debris from entering the engine.