Rick,
They are actually (usually) easy to get off. Make a mark on the shaft and on the arm so you know what position it goes back at. Just remove the roll pin (usually it is a bolt but maybe you have a roll pin). Take a screwdriver or punch and gently wedge it in the gap to spread the clamp apart a little and it should just tap off. If you are careful and dont destroy it getting it out; I bet you can take the seal to a local bearing shop and get one faster than Iseki.
Hope this helps,
