Yours may be different but ours has snaps on the outer end of the matress and on the bunk ends. We snap the matress to the snaps on the ends and leave them that way. When closing up, we then,  fold the matress at the seam. there are also snaps, on a strap, where the seam of the matress is. These snap to the base of the bunk end ( about mid point ). When snaps are in place I can remove the shepherd poles fold in canvas and then close the whole thing up.
I can do this alone by closing part way and checking each side as I close up to make sure no canvas is in the way. Hope this helps.

Our bunks attach around the inner rim of the door frame and have a flap that is screwed down under the mattress not too far from the outer edge of the door.  Other than that, there's a flap that goes under the mattress on the sides and attaches with velcro, and finally the tent is held down to the door with velcro around the outer rim. 

When folding up, I detach all of the aforementioned velcro.  I next fold the mattresses in half at the fold line, putting the bow and j-hook in between the layers of the mattress, then push the mattress about mid-way in the door.  There are two straps inside that keep everything tight to the door when folded up, they need to be connected next and left a little loose.  To fold the tent material up, I pull the roof out then let it lay flat on top of the mattress, then fold the end on top of the roof, then sides get folded on top of that.  If I do everything right, the door needs very little pressure to close up.  It's also very important that none of the tent material gets under the seals, otherwise I'll get leaks.  Lastly, I snug up the two straps inside to keep the mattress and tent material against the door, if necessary.

Not sure if this helps at all, or even makes any sense without pictures.