1. Do a backup first. Do it after hours or on the weekend when no one else is logged in. (Don’t do it during business hours.)
2. Try it with a small batch of about 10 stocks first so you get an idea of what results you will get. Export the stocks using the attached report.
3. Make your changes in Excel and save as CSV. Import them back into PS with the Import Stock Catalog feature. Use the GENERIC interpreter. PS will only accept a (.CSV) Comma Separated File
4. PS will only recognize stocks with a Stock # (No stock # = no luck)
5. If you mess it up you can always revert to your backup.