There are various ways that you can edit Packages in your Catalog.
The Edit button allows you edit the Package selected. You can also double-click the Package.
This feature allows you to update properties for multiple Packages at a time. Click here for details.
The Package Items button allows you to add multiple Items to a Package at one time. 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. .