Yooper's right. Co2 loss isn't the problem...oxidation is. you'll have to siphon it, and I would re-prime it with some sugar...maybe 1/2 of what should be used for one bottle if it wasn't carb'd at all...possibly even less.
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10