cpurvis, this is an L-head engine.
If you have a small engine valve spring compressor it is very easy. If you don’t, go borrow one from your local repair shop or some auto guys have them also. I’m assuming you are having trouble getting the small tapered keepers in the slots. You will need these, the compressor, small screwdriver, grease and a little patience. First using the compressor, compress the valve, valve spring and retaining washer as tight as possible. Second, take one keeper and put a dab of grease on the inside and outside. Third, stick the outside of the keeper to the screwdriver, with the taper up. Fourth, patience required, move the keeper into the slot on the valve and slide the screwdriver off. The grease on the inside of the keeper will keep it there. Once it is in the valve, repeat on the second keeper. Fifth, slowly release the pressure on the spring compressor and repeat on the other valve. Once you understand how it is done, takes less than a minute per valve.