Ya change the water like you would normally do, what I mean by don’t stress him is after he,s in the enclosure just leave him be. Don’t be hanging around and checking on him every half hour, and if he doesn’t want to eat for the first few days don’t stress and think you have to keep trying till does eat. Not saying this is what you will do but this what people mean by don’t stress the frog out. Some people try to keep them in just water but it’s not good for there back legs, after a while they end up haveing serious issues with the legs. I even seen on an old thread That a breeder from the US even said that it isn’t recommended to keep them that way.