Hey, hope you manage to work it out.
If it helps here is a link I used to insert a lifeline into a row that has already been knitted, I am hopeless at getting stitches back on the needle. If you go down the page it explains how to put a needle into the destination row before unraveling, you could try that. When I did it I used a needle and thread instead of a knitting needle because I thought it'd be easier, worked just as well.
If you stick a lifeline or your knitting needle in a row or two below the bind off then just unravel and pick the stitches back up off the lifeline you should be able to fix it.
There might be another way, I'm not very experienced but I would probably do what others have suggested and just unravel the bind off, pick up from the lifeline and keep knitting until its right.
Hope that helps xxx