[QUOTE=islandgirl2;523457. It is pretty easy when my leg is down at the bottom of my pedal stroke.[/QUOTE]

You shouldn't be trying to unclip when your leg is anywhere but the bottom of the stroke, fully extended. I can't imagine trying to unclip with my leg pulled up and not at the bottom of the stroke.
I have Speedplays (though not the Frogs) and it is really much much easier to unclip than with spds, which I started with and I have on my hybrid and mountain bike. Since they are free float, you should be able to just rotate your heel outward.
I know sometimes there are misconceptions about clipless... my son just got them and he thought you had to clip in both feet at the same time , until he figured it out, after falling twice. I told him to put a little voice in his head to say "unclip" when he is approaching an intersection or any situation where he might need to put a foot down. After awhile, it becomes second nature. Muscle memory plays a big part here.
And for what it's worth, the grass thing didn't help me at all. I found it hard to ride my road bike on grass and that was getting in my way... I went on the road on a Sunday morning early, and rode around with just one foot clipped in. I did that for about 2 weeks and that was it. And, I am very uncoordinated, so anyone can do it, with practice.