After couple of try and fail I found a technical way to cut and recreate contact on FPC flex cable. Here some test. And other original side on left :
Cut your fpc cable straight.
Put kapton tape on back side
And put kapton on front side like this :
Use your Dremel or any mini tool with polish paste and a polish bit.
Put more kapton on back or glue a small piece of plastic to make it more resistant. And voila !!
NB : I did not put solder (tin) on it but when I’m writing this article i think is it a good idea.