As of version 4.6 of Liberty there is a new option for bulk editing items. In the screen capture below Change Item Price Codes and Change Categories are listed separately. This was the pre-4.6 menu.

Now in version 4.6 when you go to Activities>Inventory you will see Change Item Details.

In the new Change Item Details you can do a bulk change for date received, price code, category, location and section.

In the For these Items section of the window you are setting up the criteria/filters for what accounts/items you are wanting to modify. In the Make these Changes section you are specifying what it is about those item you want to change.