Uncombining A Multiple Order

Anybody know if there is any way to uncombine a multiple order or cancel one item off it? 

not possible.  it's insane such a basic functionality is lacking but it is.  'Cancel' the item via a refund

Great thanks. That's what I thought. That is a seriously annoying issue. On a big order  you risk the buyer saying well forget it then to the whole thing.

just untick the one you want to cancel (on send invoice)