Instructions - These are very simple to take apart and put back together. There is a few videos on YouTube (search " repair Bowflex dumbbells") that show how to do this. Just be careful not to lose the springs or bearings when taking apart.
Bowflex 1090 SelectTech Dumbbell Replacement #4 (2nd large) Weight Plate (10lb)
Bowflex 1090 SelectTech Dumbbell Replacement #4 2nd Largest Weight Plate 10lb
Bowflex 1090 Only Replacement Disc Set (2, 3,4) Dumbbell SelectTech Handle Part
DAMAGED - Bowflex 1090 Dumbbell Replacement #4 (sec largest) Weight Plate (10lb)