Feel better while cleaning
Start the process by surveying the room, you have 4 walls 4 corners, and a door, do not worry about the closet yet, till the room is clean.
The first thing is to clean behind the door so it can open completely, then get about four trash bags or boxes to separate all the little stuff, and for the trash/trash. In a room where the hoarder lives, the only thing clean will be the trash can. Everything lands on the floor. They will not pick anything up, there is no care factor, no heart. So you as a parent or guardian will have to show by example, how to have a caring heart and you love your friends or kids, by helping them clean there room, it is therapeutic for the both of you or all who is involved in the room cleaning.
Start with a deep breath not too deep a breath, then say, Oh god please help me and us through this cleaning process please, thank you, Lord, then push some of the stuff to the side to make a clearing behind the door to see if the door does function and close.
Then take a trash bag to pick up the stuff on the floor in a 5-foot area to make room for making plans for what will be next to do, look at the furniture, big stuff in the room how do you want them to be placed in the room, 10 million decisions later your room will be looking better, all the little stuff is in 5 bags in the corner, the furniture is where you want it to be, then you go through the bags. All cloth go in the closet, all writing things go in the desk, all jewelry goes in…