We removed the top bunk in our 2400bh. This is how we did it:
(1) Remove all the window shades and valences from the top and bottom windows its just a few screws. then remove the top plywood sheet by removing all the screws. It is in 2 pieces. keep one piece to sit on while removing the support screws.
(2) Find a 5yo, if your very light start at the back and work you way out as you remove the screws around the edges. Here is where my 5yo helped as I am not a light weight person.
These were the screws she was in charge of.
(3) remove the front trim board.
(4) Using an exacto knife, I cut the seal between the wall and the bunk. (It did not fall on my head)
(5) push up on on the side nearest to the window.
(6) Enjoy a fully functional “extra room” in your camper.