If your total voltage is over 10 on the main leads it may just be the balance lead after all. Open the end of the battery pack, very carefully without contacting any metal parts with the knife or puncturing the cells, and measure the tabs on the cells if you want to proceed with this route.
You cannot charge the battery by modifying the balance lead without removing the damaged cell itself from the main series connection. It will puff up for sure and might catch fire. The balance lead is not for the main charging current, but for monitoring the cell voltages and slightly adjusting them. All the current will still be passing through that dead cell, but it will be completely unmonitored which is a recipe for disaster.
As per a discussion we had on another thread, if you measure the voltage between the tabs on the cell to be truly 0.00v, you could solder a jumper over it, effectively removing it from the pack. You will then need to rearrange your balance leads for the new 2s battery configuration.
Otherwise you need to desolder the tabs and remove the cell from the pack physically.
"Kind of work" is not good enough in the world of lithium cells, it tends to lead to either a dead pack or a fire.