To Delete or Rename a Saved Gallery:
Open the Galleries palette (Window > Show Galleries).
Select the gallery that you want to delete or rename.
From the palette fly-out menu, select either Delete Gallery or Rename Gallery.
or
From the Window menu choose List Galleries..., or press Command+Option+G (Mac OS) or Ctrl+Shift+G (Windows).
The Saved Galleries dialog box appears.
Select the Gallery you want to edit.
Click Rename&ldots; to rename the selected Gallery, or click Delete to remove the Saved Gallery from the catalog.
Click Done to close the Saved Galleries dialog box.