I don't remember off the top of my head if it was the old, righty tighty lefty loosey thing our not
When mine first got stock, it was completely apart like your photo. I put a vert grip on one side of the RIS and one on the other..(2) and then put the upper body between my legs...I hardly had to put any pressure on it with that set up and the entire RIS and Delta ring part let loose from the body. Then you just unscrew the RIS from the delta etc once its all apart.