Channel is now editable on existing sales05 Apr 2015
You can now change the channel on existing sales. You can do this by clicking the 'edit' link next to the channel name on the sale details page. Please note that after order confirmation, you will only be able to switch to a channel of the same currency.
When changing channel, you will have the option of repricing the sale with that channel's pricing. Only the original order pricing will be updated. Existing invoices, shipments etc will not be updated. To update an existing invoice, you will need to delete and recreate the invoice.