Broken valve springs and faulty valve stem seals are not hard to replace as they do not involve taking off the cylinder heads, only two special tools and a source of compressed air are necessary. Start by emptying the valve cover and camshaft and lifters, then extract the spark plug of the affected cylinder, or all of them in the event of replacing all valve stem seals. Pump the lever until the piston reaches the top dead center on the compression stroke, stroke by stroke according to the firing order. Insert air hose connector in spark plug hole and use air to find a method of clenching the valves. Use stuff rags to cover the valve holes to keep parts out of the valve holes and then lightly tap the valve spring retainers with the keepers. Compress the spring with a valve spring compressor and take out the keepers with pliers of a magnet, being careful of the right type of tool to use (Import or Import type). Wipe the valve face and the seat and pull out the valve spring and retainer carefully so as not to destroy the part of the face or seat. Loosen up the old valve stem seals with needle-nose pliers, place a rubber band or some tape on the valve stem to stop it from falling and then inspect the valve stem and see whether it is damaged. Reinforce air pressure to hold the valve in place, lubricate the stem with engine oil and replace a new seal. Install the valve spring and retainer, compress the spring, and it is important to install the keepers in the groove with grease to hold them in place. Finger the spring tool, dis- attach the air hose and re-attach the camshaft, lifters, timing belt and valve cover. Lastly, it is time to install spark plugs(s) and ignition coils(s), start the engine, and look at possible oil leaks and strange sound.