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.