Shower Door Repair I Have A Glass Shower Door That Is Not Align. Several Balll Bearings Are Not With The Glass Doors?

I have a glass shower door that is not align. Several balll bearings are not with the glass doors? - shower door repair

I wonder whether I, the parentheses and solve the ball in square brackets. Please tell me your ideas on how to repair a shower door, glass slides are not easy / closed.