I had to do this about 7 or 8 months ago with my 1800E. Just slip some rope in the cylinder, crank around by hand until the engine locks up, and use a spring compressor to pop it off. I have a little cheap one that just grabs the spring (which wouldn't work with double valve springs - or at least it wouldn't compress the inner spring). You might think about putting a new valve seal on while you do this - very cheap part - very easy to replace once the spring is off.

Murphy's law, but in my case one of the little keepers (collets?) fell off the valve stem, did a bounce or two and made a hole in one into a pushrod hole. With the pushrod still in it! Had to be just spot on to make it down the hole. And it didn't land on the lifter or nearby either - I looked with a flashlight and fished with a magnet for a while. And it didn't come out when I changed the oil. *SIGH* I doubt it will cause a problem though.