No biggie to do them. Just set the engine like you are doing a valve adjustment. I used a small hand held valve spring compressor, with a starwheel to tighten. It worked ok. Pull the rocker, install the tool, tighten the handle. The valve should sit on the piston. Tap the tool gently to release the keepers. Word of caution, put a rag around stuff to catch the keepers. I thought I lost one in the bottom!

A small magnet is helpful too. Use the magnet to pull the keepers, pull the spring. Put the new one in the compressor, twist it a little to make sure it's tight in there, put it on. Small dab of grease on the keepers, put them in with needle nose. Pull the spring up to hold them in place, back off compressor.
I just went and did them in the firing order. I compressed the spring, then turned the engine a little to make sure the piston was on top. I could see the valve move. Then put the rockers back on, adjust valves in sequence. don't know what others adjust them at, but I did .008 and .018 instead of 10 and 20.
Hope this helps.