I don't know how I missed this post yesterday. But, like Fourtrax said, the centrifugal clutch has left hand threads, so turn it clockwise to loosen. The centrifugal clutch is pressed on, but I've took a lot of them off over the years and I've never had to have a puller. Sometimes they are easy to get off and sometimes they are a little harder to get off. Sometimes, I have to use both hands and pull very hard to get them off. I usually give the side of the clutch a little rap with a hammer to jar it before trying to pull it off. Don't hit it hard enough to damage anything, just a quick rap to jar it. If for some reason you still can't get it off, you may have to get a puller.
For the other clutch, you won't need to remove the nut, looks like you've got the clutches ready to come out as soon as you get the centrifugal clutch off.