Be very careful here.

My configuration was slightly different, the blue tools were too wide to open the connector. I used the tip of a sharp knife and used very little pressure and wiggled upwards the connector from all four sides. Do not push sideways under any circumstances!! I needed ten minutes for this step. I luckily didn't break anything. I was scared when the battery cable finally fell out. I didn't expect that it was just the end of the cable with four visible contacts. To connect the cable of the replacement cable, bend it 90 degrees down so that it goes into the open connector, then carefully push down the connector. It should go down with a very little click. If you are unsure whether you have power, don't close the ipod yet, but connect the ipod with power and wait about 15 minutes.

It was very hard for me to open the case. It took me about forty minutes for this step alone. Try to keep the gap open with a different tool while you work around the edge to a different side. I wished I had a third hand. One to hold the ipod and two to hold the two tools. The top cover bends slightly but this is not a problem, because it's just protective plastic. The clips at the sides also break slightly. Remove the really tiny bend plastic parts because they will be in the way when reinserting the cover (by just pushing the cover back into its place).