Attached is a Package Builder archive of the XML apps and associated action menus to allow right-click > bulk update of content items.
One set for Community update, one set for expiry/reminder date update.
After deploying you’ll need to modify the action menu ACLs as appropriate, and go into the Visibility tab of the action menus to set the correct content types/roles and states for their use. By default (and recommended) these menus should only be available for content in an editable state. Also, don’t assign content types that don’t have both expiry/reminder dates included to the bulk date updater since it sets both of those. You can always easily modify the XML/XSL if you need to update different fields.