Selling items no longer using

My husband if 50 plus years has just started the last 2 yrs. Of major memory issues as well much anger. Nothing has been diagnosed, many MRIS show normal aging sight's However talking with his Dr. he has opened up that he loses items, can't remember what day it and questions me through the day what day is it? So after his mental status this is the issue, we have a boat as well as as a RV that need to be gone, sold. He refuses to let go of them, he is aware they in need to be gone. Our family brings this up and he gets VERY angry. How can we take over and sell these items.