Rebuilding DeWalt XRP 18V Packs.. Help?

[rawfuls]

Hey guys,

My dad's old packs finally have died..

We have two, one measures ~7.4V using the main + and - terminals, when measured with the + and middle (I assume kinda like the balance port), also measures this, when measuring the - and the middle, nothing. Sounds like one group is dead to me, or there's a short/open circuit here.

The other pack is 0.00V across the board...

We've taken the cases off, and I'm starting to chip into the glued, uhm... cardboard... to try and measure each individual cell to whether they need replacing or just need to be cycled...

Is there anything I need to be wary of? Or any tips?
I was never found of the 'balance port' so any insight on that would also help.
In addition, links to good, recommended new Sub C cells would be awesome!

I know a few of you have tried this, and some succeeded, so just looking for input, thanks!