I wanted to ask if you can change the difficulty of survival mode on a started world again. LG
https://minecraft-de.gamepedia.com/...difficulty
Do you mean this?
For the difficulty easy / difficulty {number}
0,1,2,3 so peaceful, simple, normal, hard
If you can't cheat just open world in the LAN and then activate cheats in the menu (you just have to do every session you want to cheat)