In order to take stock out of the Committed stage, you'll need to fulfill the order that is committing the stock, which will deduct the stock from your On-Hand inventory. Alternatively, if the order is no longer needed, you can Void the order, which will take the stock out of the Committed stage and revert back to your Available stock levels.
Please note there isn't a direct way to edit the committed stock value other than the methods mentioned here.