After purchasing & downloading order page from Hostbill Licenses Client Area

1. Extract downloaded archive contents in main HostBill directory on your server
2. In HostBill, proceed to "Settings->Products & Services"
3. Select existing Order Page, or create new one

4. Click on "Edit this Order Page"
   
   
   
   

5. Save changes to save orderpage settings. 
   
   

You can now edit your products under this orderpage, following product description setup:

Will result in following order page layout: