Navigation → Documents → Processing → Sales Orders → Select Sales Order from List and Double Click to Open
If changes to the Qty to Process must be made follow these steps:
1. Select Document Lines tab.
2. Change the Qty to Process.
3. On top tool bar select the Generate Invoice from Sales Order 
icon or click Processing on top menu and select Generate Invoice from Sales Order.
4. Save using the save 
icon or CTRL + S or CTRL + Enter to save and close.
Invoices generated this way will be linked to this Sales Order. If you go to the Processed tab and then to the Invoices tab, you will find all the Invoices linked to this Sales Order.
