I learned this method from fietsbob on another thread.

Leave the heavy chain whip tool at home. Instead bring some zip ties. Lash the cassette to at least three spokes to stabilize it. Leave the heavy wrench at home. Borrow one from any hardware store, RV traveler or repair shop. Just bring the small lock ring tool. I just tried it. It works! Three zip ties came close to snapping. You may need more.