While trying to remove some of the interior trim I made the mistake of removing one side of the sun screen. As you would expect the assembly is under spring tension to assist in re-rolling the fabric. I had not anticipated the fact that the only thing holding it together was the screws holding it to the car. So as soon as one side was down the tensioning thread popped off the spool holding it. It took a couple a couple of beers and some thinking to figure out how to get it put back together and then how to get it back in the car in one piece.
The tensioning thread runs from the spool (1) forward to the front pulley (2) then back to a guide (3) and clips to the spring which sits on a pin (4). If it just fell down from it's mounting after you removed the last screw it won't look like this.
1: unclip the spring from the pin (4) and remove it from the guide slot (3) and lay it out on the floor ahead of the front pully. Do this for both sides.
2: keeping the shade as straight as possible, wind it around the roller into the fully open position. At this point the tensioning thread will be wound around the spool.
3: pull outward on the socket until it clears the pin on the end of the spool. Pull the winding thread off the spool to the side and put the pin back in the socket. Do this for both sides.
4: take the spring and run the thread through the guide(3) and leave it laying in the slot, don't put it on the pin yet. Do this for both sides.
5: re-tension the shade on the roller & make sure that it is straight. pull the pin from the socket again and run the tensioning thread around the back of the spool from bottom to top. It should be resting on the thick part of the spool. It will want to drop down between the pin and the socket or over the top onto the roller. You may have to go back and adjust this if it moves during the rest of the process. Do this for both sides.
6: make sure the thread runs forward & over the front pulley. It will probably be to one side of the pulley instead of on it. Its easiest to use a #20 torx to remove the pully & center the thread. You may have to repeat this too as you finish adjusting. Do this for both sides. The picture below shows the thread run incorrectly, its off to one side.
7: check that the thread is correct on the rear spool and front pulley then clip the end of the spring over the pin(4). Do this for both sides.
If things have gone correctly the shade should be under slight tension holding it open & it should resemble the first photo. The next problem was how to keep it together. If you pick it up the spool pin will pop out of the socket, the thread will come out & it's back to square one. I tested this.
The solution was to tie a loop of string through each of the rearmost mounting holes. The two loops should not meet if you pull them together. Size it to leave an few inches between them when they are under tension.
Very carefully, with your hands over the socket on each side, turn the shade over so that the underside of the shade is facing up. Pull the two loops toward each other and use a zip tie to tension the assembly enough to hold it together but not hard enough to break anything.
You can now re-install the shade in the car. Support the shade by the roller with one hand and put one of the center screws in on each side but leave them loose. Install the rest of the screws but don't tighten them yet. Cut the string loops & remove them. Snug each of the screws then test the operation of the shade & adjust them before the final tightening.
Or just don't mess with the thing in the first place. That would be my recommendation.