Try to make it a close up of one of those tabs, and if I can't see how to take it off, I'll bet some of our other members will. I've had 4 different types myself, but suspect there are even more out there. Do you know whether the driveshaft is fully collapsed or not? You can always just pull it apart, as I mentioned, but if it isn't already fully collapsed, you might hold a block of wood over the end of the driveshaft and give it a sharp rap with a hammer; i.e., drive it together a little bit, because I suspect once you move it just a little, then it'll go ahead and slide back and forth.