If the bad lipo cell is just balooning I heard a story about keeping it in the fridge at very low temp to recover it...I never tried and do not suggest it because as we know lipo can burst...but maybe somebody else heard the same story and it can really be done....
To remove the broken cell from the pack is possible too, you have to open the shrinking tape and see how it is connected, just be carefull that if you need to weld the lipos contact you may need a special liquid, sorry don't know the name in english, otherwise welding will not hold.
The 2 4s may be transformed in 3 2s and you drop the 2 broken cells

cheers