its quite simple once you know what you are doing. first, you need to go shopping. you will need to rent a valve spring compressor, autozone does it for free.
you will also need an air compressor to hold the valves up while you have the spring removed. you can grab one of these fittings from a compression tester, or I can send you mine.
first, remove the valve covers, and the rockers. then to make sure the valve'* dont drop into the cylinder, you need to pressurize the chamber. this is done with the fitting and compressed air.
then, put the spring compressor tool on the spring and compress it. you will be able to feel if the valve is tight, or if it is going to drop. DO NOT let it drop, as you wil have to remove the head, $$$.
do the springs one by one, use a magnet to remove and apply the retainer locks.
i dont really have much to add, other than, take your time.