So you broke the rear door handle and now you can't get in.
This is a step by step for a 89 Safari Sle with the standard barn doors and full plastic trim and panels. It should work on any barn door van. As I have not tried it on a dutch door van I have no idea if it will work or how they even latch.
Step one: Go to the inside of the van and remove the speaker cover from the passenger side door. The cover should just pull off although you might need a slotted screw driver to gently pry the cover loose.
Step two: Unscrew the speaker and gently move it up and out of the way. The speaker on my van had nuts on the back of the screws which made it difficult to unscrew. I used a drill and pushed lightly on the speaker to put tension on nut the speed of the drill helped to get the nut off.
Step three: Reach through the speaker hole and over the licence plate holder in the door untill you feel the rods that lock and unlock the door and open it. You might need to employ a child to reach through hole as its kind of tight. ( my arm wouldn't fit) Once you can feel the rods pull up on one of the rods and the door should open. You can have someone use the key on the outside of the door to lock and unlock the door so you can tell which rod to pull. (you want the non moving one)EDIT: AS POINTED OUT TO ME IN ANOTHER THREAD THEIR IS ALSO A TOP ROD WHICH WILL HAVE TO BE PULLED IF THINGS ARE TOTALLY BUSTED INSIDE. BUT IF THE RODS ARE STILL CONNECTED TOGETHER THEY SHOULD MOVE AS ONE AND THE DOOR SHOULD OPEN. I forgot about the top rod since I didn't pull the rods myself since my arm wouldn't fit far enough into the door.
Step four: when you have the door open remove the door panel from the inside and tie a peice of fishing line around the top of the rod and run it up through the plastic panel so that the next time your handle breaks you only need to pull the string from the inside to open the door.
I hope this helps.