Once you have the retainer seated in the bezel, place the bezel face down on your watch face placing the side with the split in the retainer down first. If you do not do this, the retainer may not seat properly, as shown in the first photo.

If that happens, gently pry the bezel and retainer up by hand, re-seat the retainer in the bezel, and try again.

Once you have successfully replaced your bezel on the watch, it should feel like new and rotate freely again.