sochen cave palaces pilgrim door

[Nominus Experse]

You have to change the various waterfalls' courses by exiting and entering select doors in order to open this door.

EDIT: SOLUTION!!!
Do you like ty MS Paint Art? I sure do. Here is my quick drawings of what you need to do in order for the waterfalls to change. You will hear a sound and a messege will appear whenever you do it right. The maps ought to be self-explanatory.

And do not complain about the quality of these things: I made them in five minutes in MS Paint...