One month ago I replaced the cord on the passenger side 5 ft. shade in my 2005 Journey. It may or may not be configured the same as your problem shade in your Adventure, but here is what I encountered and did:
My shade is held up to the top underside of the valance by two Phillips head screws (one on each end) and a plastic clip in the center. Since there is little space between the valance and shade, I purchased a long-reach (16") #2 Phillips to reach the screws. I had to removed the screws with the shade down to give me enough room to reach up there. I then had a tough time pulling the shade from the clip (dear wife held shade inside the coach and I, reaching through the open window from the outside while standing on a ladder, pull it down and out of the clip).
After some research I found the following link to the WIT Club News article which gives an excellent description on how the shade is strung and how to restring it:
http://www.winnebagoind.com/resources/service/pdfs/2006-09%20Restringing%20Day%20Night%20Blinds.pdf.
It may look complicated, but it really isn't. The "spring" at the top was covered with a piece of masking tape. We replaced it with new masking tap when we strung ours.
We used a restringing kit sold by Blind Man Jim. http://www.gotbrokenshades.com/id8.html
The kit that Blind Man Jim sells not only contains the replacement cord, but also a cord needle (twisted wire loop), and the correct size "cord guides" (grommets) which are plastic bushing inserts that prevent the cord from rubbing against the sides of the holes in the metal top and bottom parts of the shade. The kit also has a decent set of instructions which complemented the WIT instructions. The cord needle was very helpful in the restringing process and the cord guides are essential. The kit is a little pricey, but for going through the process for the first time the kit made us fell much more comfortable in doing it. Sure, you could get the cord at Joann Fabrics, but I don't know where to get the cord guides which are critical in reducing the wear of the cord.
It took both of us to restring the shade on our dining room table. So a partner is essential, unless you are an expert on stringing shades. Time from its removal to finishing the stringing was about an hour.
Re-installation involved reversing the process for removal. It again took both of us to get the top bar of the shade to "click" back into clip on the underside of the top of the valance. It took about 15 minutes and involved rocking the bar back and forth in the clip with my wife holding the shade up while I manipulated it from the outside through the window. The major contributor to this difficulty is the very tight space one has to work in. Whew!!! Of course the screw holes on each end didn't quite line up when we got it re-clipped. More jiggling and juggling finally got us close enough to the original screw holes so that we could put screws back in using the long-reach Phillips.
Yes, we are still married!
Suncircles
2005 Journey 36G with CRV Toad