There are various ways that you can edit packages in your catalog.

The Edit button allows you to edit the package selected. You can also double-click the package.

This feature allows you to update properties for multiple packages at a time.

Check out this article for more details.

The Package Items button allows you to add multiple items simultaneously to a package. The Update Package Items dialog is shown below.

Use the Add Product and/or Add Labor buttons to select the accessories you wish to add.

You can choose to append to the existing accessories or overwrite the existing accessories.

You can edit packages within the Project Editor using the edit button or by double-clicking. You can also select multiple items in the Project Editor and choose to add them to an existing package in the project via the Add Selected Items To button.

The packages will be project-specific unless you use the Update to Catalog feature.