A vehicle door structure includes a panel and a bracket. A window opening in the panel has an edge extending along a lower periphery of the window opening from a first side to a second side of the window opening. The edge defines a seal supporting lip and a glass installation slot. The seal supporting lip extends from the first side of the window opening toward the second side of the window opening to a terminal end of the seal supporting lip. The glass installation slot begins at the terminal end of the seal supporting lip and ends proximate the second side of the window opening. The bracket is removably attached to the panel filling the glass installation slot. The bracket has a lip extension aligned with the seal supporting lip extending from the terminal end of the seal supporting lip to the second side of the window opening.