Steps:

1. Go to Inventory > Products > Import/Export
2. Click on the Export icon in the right-hand corner
3. Open your product export CSV file 
4. Scroll to the left until you see the "Obsolete" field 
5. Under the field, change the product cells you want to delete to 'Yes'
6. Save the file and go back to the Import/Export page 
7. Drag your product file or upload it to the page 

Note:

Please make sure to zero out the stock on hand, as well as no open transactions before bulk obsoleting those products.