Then open IM and go to FILE > IMPORT > PRODUCT LIST IMPORT
Pick the new file you created from the IMPORT FILE box.

If your file is a CSV then the DELIMITER USED will be a ,

Click Match Fields and the following box should come up next.

Then click on CHOOSE PRODUCT LIST and the system will check if the ISBNs are in stock. If items are available then it will create a list of those items.