Click the 'Upload Inventory' link under the 'Inventory' heading in the Control Panel.
If the data file contains a mixture of items for addition, modification and deletion, select the 'Add/Modify/Sold (all one file)' option from the 'Upload Type' drop down menu.
If the data file contains only items for deletion, select the 'Sold Books' option.
Then, click the 'Choose File' button next to 'Upload File' label to select the file you want to upload.
If the file you are uploading is a purge file (it contains ALL of your in-stock inventory), turn on the toggle switch next to 'Purge inventory?' label.
If the file does not include your entire inventory, keep the toggle switch off.