[bruce750i]

Your lucky it's an outside cell.

I would un-stick the bad cell first. use a warm to hot butter knife slowly cutting foam tape between the cells. once apart stick some paper between cell to keep them from sticking again.

Cut off dean wire lead(looks like the positive) at bad lipo. cut other tab of the bad cell, solder dean wire back on the positive side of the 3 cell pack.

This way your not fighting pools of solder cooling on you when your trying to unfold cell tabs.

The last time I did this the bad cell started getting hot after removing one of the tabs so I had to move quickly to finish the amputation.