I agree with cypher on the levels, hamsters really aren't climbing animals and would much rather floorspace to run about in than things to climb on. Most hamsters climb to try to escape or to cause trouble rather than to enjoy their surroundings. Getting a large bin, as cypher said, would be the best for him so he could truly enjoy his enclosure. If you are absolutely set on using his old cage and levels, use wire cutters like mentioned. Also ensure that you fill the cage with sisal hammocks and seagrass baskets to make sure that if your hamster did fall, he couldn't fall more than two inches. Have fun creating a new cage for him and post pictures when you're all finished so we can see your awesome setup!
