Broken valve springs can usually be fixed without removing the cylinder head from the engine. Compressed air is used to hold the valve in place while the valve spring is replaced. The tools needed for this repair are commonly available at auto parts stores and from tool distributors.
Remove the spark plugs from the engine.
Remove the valve cover.
Rotate the crankshaft until the piston in the cylinder you're working on is at the bottom of its power stroke (both valves closed).
Remove the rocker arm.
Screw the air hose adapter into the spark plug hole, and apply 90 psi of air pressure. This will hold the valve in place while you replace the valve spring.
Compress the valve spring using the valve spring compressor, then remove the valve locks and retainer.
Install the new valve spring. Set the valve spring in place, with the retainer on top. Compress using the valve spring compressor, and reinstall the valve locks.
Reinstall the rocker arm, valve covers and spark plugs.
