That's a problem with tight rebuilt engines, loose worn out tires engines done stick as easy.

I would start with spraying in the Kroil, then use a flat screw driver between the valve stem and lifter to raise the valve some, once you get it to move up it shouldn't take much to work it loose, sometimes a large flat blade screw driver in the spring turned sideways to add pressure will help.

Update:

Per Chad's recommendation, I injected Acetone in through the spark plug holes right on top of the intake valves so it would run over the valves and down the stems. I did that on and off for 10 minutes. I was getting Acetone trickling out the carburetor throat. Number 2 intake valve freed itself and popped back down. Number 1 intake however would not budge. I tried prying with my largest screw driver just as Steve A had suggested using a wood block across the bottom of the intake manifold to pry against. All it did was flex the screw driver. Now it was time to use the Kroil. I injected it over the top of the number 1 intake valve on and off for an hour. Until it too would drip out of the carburetor. I took a 3" 1/4 drive socket extension and taped up the end. It would drop down in the spark plug hole and rest on top of the stuck intake valve. Then I got some scrap wood to use as a lever. I pried against the bottom of the fuel tank. It took more pressure than I thought but slowly the stuck valve closed. I sprayed more Kroil on the lower side of the valve stem and then rotated the engine. The valve would go up and stick again, but each time I pried it down it got easier and easier until it finally returns itself. I had to get to work so that is where I left it. Today I need to run out and get some ATF! Great advice Chad on that! Hopefully this will not happen again.
Thanks everyone for your help and suggestions. I am so glad I did not have to remove the cylinder head. I learned some valuable tips the last couple of days!

WE used to have stuck valves in a Gray marine engine in a sail boat where I worked. Each spring we would take the plug out of the offending cylinder(s) and place a brass rod down the hole to the valves. The wasn't much clearance between the top of the engine and underside of the deck,(approximately 8") so we'd place a long piece of wood lath over the rod to push it down. By turning the engine over with the starter and pushing the valve back down with the lath each time it stuck, it would eventually free up and be good for the rest of the season.