There are all kinds of tools to remove these GM "Jesus" clips, here are just some of them. The best one and easiest to use is the Lisle 35200. The black one second from the top has a place on the raised end to push the clip back into the door handle, but you can do it easily with your thumb nail. You push the clip back into the door handle and then just push it back on the post and the clip will seat.
No one lives forever, the trick is creating something that will.