Side door insulation?

My CTC has a 4ft side door and while I am wishing it had a more normal sized RV door due to the wall space lost, it's a little too late now.
I am curious if anyone has taken one of these apart to insulate them? The manufacturer has filled all the big torx heads for the hinges with silicone, almost as if to say "just don't".
While I am tempted to start taking it apart, it seems very hollow except for the cross braces where the 3 hinges mount to the door panel.
As I am going to install a window between the top braces, I am wondering whether I should try and pack it with insulation from that hole once I cut it, knowing I'd have to do something different for the bottom half, unless I just left that bottom part hollow.
The best I have come up with in my head is to do the top when I cut for the window and then cut a panel out of the luan on the bottom to access and fill it and then use a sheet of that white laminated luan to cover it all up after.
Anyone insulate one of these before and have any advice?
Thanks!!
I am curious if anyone has taken one of these apart to insulate them? The manufacturer has filled all the big torx heads for the hinges with silicone, almost as if to say "just don't".
While I am tempted to start taking it apart, it seems very hollow except for the cross braces where the 3 hinges mount to the door panel.
As I am going to install a window between the top braces, I am wondering whether I should try and pack it with insulation from that hole once I cut it, knowing I'd have to do something different for the bottom half, unless I just left that bottom part hollow.
The best I have come up with in my head is to do the top when I cut for the window and then cut a panel out of the luan on the bottom to access and fill it and then use a sheet of that white laminated luan to cover it all up after.
Anyone insulate one of these before and have any advice?
Thanks!!