If your goal is to change the dream environment itself rather than just your progress, the LSD: Dream Emulator Wiki suggests using: For modifying the game's ISO files.
Ръководство :: Save Editor / Редактор сохранений [HLSE ONLINE] lsd save editor
An typically refers to a tool used to modify save files for the 1998 PlayStation cult classic, LSD: Dream Emulator If your goal is to change the dream
Because the tool is obscure and abandonware, you won’t find it on mainstream sites. Reliable sources include: a Gray Man-free world
You should now see the changes reflected—either a 100% Dream Index, a Gray Man-free world, or a fully unlocked gallery.