I would try and not be in this position. Really the ideal move is to shorten up your legs and get back to the guard. Bend the knees and wrap around the body to get back to guard.
Thanks Ironman. Any tips on preventing someone posturing up in your guard, steping into it holding your feet up and sitting on top of it, pinning you down with your own knees on your shoulders?
It's about connecting your elbows and your knees. As Frank Shamrock says, "be the ball."