Thanks! I am considering replacing all cells if I manage to procure new ones from somewhere. $14K for a new battery pack is daylight robbery.
http://mmc-manuals.ru/msb/BASE/003/2015/MSB-14E54-001B/E/MSB-14E54-001B.pdf contains detailed instructions down to the cell level.
Do you think a battery module can easily be disassembled to replace individual cells or to tighten their terminals, as you said? I hope the cells aren't glued together with some compound, are they? Thanks!