I used the provided Allen wrench to see if it could be done with that - it can. However, they are very comfortable and still my favorite casual kick around shoe to wear along with my flip flops. 旧モデルがダメになったので新たに購入。靴底も丈夫で長年履きました。少しデザインが変わりましたが、基本的には同じです。大変満足です。 I normally use Acure vegan skincare but this is now my second choice. I bought a pair for myself, kept his and replaced his with a new pair. My son loves his crocs, my daughter has a couple pairs too. I love these birks! Got them yesterday. Bottom line. Its because the tongue is some kind of rubbery synthetic material.