Hello; Take the rocker shafts out, the rockers off, keeping intake and exhaust separate. At this point I usually put the engine in a big ziploc freezer bag, in case anything flies away. Then I put a socket into the bore to keep the valves from opening. Next you have to compress teh valve spring, exposing the keepers, then you have to slide the keepers off the valve stem, then release the springs. and valves. replace all parts in their original positions.
I've found that if you have the right socket, you can hold the engine in one hand with the fingers free to compress teh spring, then poke the C-clip off with a tiny screwdriver.

Hope this helps.