Before I install all my ideas in the unsuspecting van I had to remove a few things: the two captains chairs had to go (there are only two of us), and the rear bench ... well that definitely had no place in the van. It is 4.5 feet long when horizontal, enough for very small people to sleep on. In addition, ours didn't work (was stuck in the down position).
You can see one of them still there in this photo... We eventually decided we didn't need this one either. The captains chairs are pretty easy to remove - you pull the release and carry it away. Not so easy
for the rear bench/bed. The bed is anchored through the frame with 4 very large bolts, about 10mm, with serious washers and big nuts. The good news is that this is pretty secure. The less good news is that after 8 years these fasteners have turned to solid rust, as in it's not letting go with any amount of penetrating oil.
It took me about 3 hours with an angle grinder (best tool I had) to reduce the nuts below the van to powder. I was covered with rusty dust, and it is generally not a job I'd do without a respirator. If I had confidence in my precision grinding I might have attempted this job from the top, but I figured I'd destroy the carpet. Eventually the bench was free ... and very heavy. I carefully wheeled it around on a handtruck, as carrying it was out of the questing for me alone, and alone I was that day.
In retrospect, if you have a very nice set of high quality metal drill bits, drilling out would be easier - there is limited clearance to get a cutting tool below the nuts.
Now I had a nicely padded, but empty, cargo van. On to the new bed.