I've never been a fan of Oetiker clamps because I never had the right size, they were single-use, and it seemed that they were expensive to buy. I use them a lot more now because I've found that they are relatively cheap on Ebay, they are quick to install, and unlike wormgear clamps they don't come loose. Until recently, I've thought that Oetiker clamps were difficult to remove. Here's the easy way.
If you look closely at a typical Oetiker clamp, you'll see a small tab that sticks through a slot, then is bent over to lock it in place. (SeaDoo had some re-usable clamps, but this doesn't apply to them).

Use a small pair of flush-cut diagonal cutters to grab onto the tab and the opposite edge of the clamp:

Squeeze the cutters to bend the tab upward so it can slide out of the slot:

Stick the jaws of the diagonal cutters under both sides of the band and pry it up:

The band is now separated and can be unwound and removed easily:

Enjoy!
If you look closely at a typical Oetiker clamp, you'll see a small tab that sticks through a slot, then is bent over to lock it in place. (SeaDoo had some re-usable clamps, but this doesn't apply to them).
Use a small pair of flush-cut diagonal cutters to grab onto the tab and the opposite edge of the clamp:
Squeeze the cutters to bend the tab upward so it can slide out of the slot:
Stick the jaws of the diagonal cutters under both sides of the band and pry it up:
The band is now separated and can be unwound and removed easily:
Enjoy!