What is the first step to update an Essbase cube using Cube Designer after exporting it to the application workbook?

The first step to update an Essbase cube using Cube Designer after exporting it to the application workbook involves selecting "From Sheet" to populate the wizard with the contents of the application workbook. This action is critical because it establishes a connection between the Cube Designer and the exported workbook, allowing the designer to retrieve the necessary data and structure from the workbook for further modifications.

By selecting "From Sheet," you ensure that the Cube Designer accurately reflects the latest changes or configurations that might have been made in the workbook, thus enabling a seamless import of the cube's metadata and design elements. This foundational step sets the stage for any subsequent updates, like adding new dimensions or members, as it ensures all relevant information is already in the Cube Designer, ready for further actions.