You will need the Full Write Resources permission to form this action.
Go to "Events > Resources" in the left navigation menu and select the "Items" tab. The list of items will appear in the table. Open the drop down menu at the end of the row containing the item you want to delete and select "Delete."
A confirmation message will appear making sure you want to delete this item.
You can also do this while viewing the item details by selecting "Delete" from the "Actions" menu.
The item will not be able to be deleted if there are any requests for it.