G Plan form 5 doors  

I've seen these with the ingenious plastic tracks that allow bypass doors to sit flush with each other when closed, but I've never had to disassemble one. Maybe some sort of spring-loaded hardware like bullet catches are mounted to the tops and/or bottoms of the doors? Try feeling around under there with something very thin and rigid, yet flexible, like a piece of stiff plastic cut from a beverage bottle. It may be that you'll need to "shoehorn" the doors out, if that makes any sense...