1. Obtain the necessary tools, including a feeler gauge, a screwdriver, and a wrench.
2. Position the car on a level surface and allow the engine to cool down if it has been running.
3. Lift the hood of the car and remove the oil filler cap from the engine.
4. Locate the four valve covers on the top of the engine.
5. Remove the valve covers using the wrench.
6. Use the screwdriver to turn the crankshaft until the piston in the first cylinder is at top dead center (TDC).
7. Insert the feeler gauge between the rocker arm and the valve stem of the first intake valve. The gap should be between 0.004 and 0.006 inches (0.10 to 0.15 mm).
8. If necessary, adjust the valve clearance by loosening the locknut on the rocker arm and turning the adjusting screw until the gap is correct.
9. Repeat steps 7 and 8 for the remaining three intake valves.
10. Turn the crankshaft 180 degrees until the piston in the first cylinder is at top dead center (TDC) for the compression stroke.
11. Insert the feeler gauge between the rocker arm and the valve stem of the first exhaust valve. The gap should be between 0.008 and 0.010 inches (0.20 to 0.25 mm).
12. If necessary, adjust the valve clearance by loosening the locknut on the rocker arm and turning the adjusting screw until the gap is correct.
13. Repeat steps 11 and 12 for the remaining three exhaust valves.
14. Replace the valve covers and the oil filler cap.
15. Start the engine and check that it is running smoothly.
Remember, incorrect valve settings can affect engine performance and fuel economy, so it's important to adjust them accurately. If you're unsure about how to adjust the valves on your 1973 Beetle, consult with a qualified mechanic or refer to the vehicle's repair manual for additional guidance.
