yeah basically that is the best advice follow what fmb says =)

if you want to bring it back, put it on a wallwart type lipo charger for about 10 min until the voltage comes up above 3v, and then hurry and stick it on your other charger. Be prepared for it to blow up or burst into flames at any second though, I would also cycle it 2 or 3 times after you get it charged just to make sure it wont kayto in your heli. Honestly though you can get a new pack for like 20 to 40 bucks, and it's really not worth the risk.

If the battery is below 2.75v on that cell though, do not try to rescue it, just dispose of it. Discharge the battery to 0 volts with a 1/10C load for atleast 10 hours, like an automotive light bulb or a sandbar resistor or something. Cut some slits in the sacks and put the pack in some salt water and let sit for 24 hours. Throw the battery in the normal trash and dump the water down the drain. no hazerdous chemicals in lipos =) Other batteries you need to take to a recycling facility.