1. Desolder MCU
2. Reball it
3. Remove 1 ball from position N1 (marked on picture with red dot)
4. solder MCU back
5. Flash phone with older version with option "software restore cutted track"
6. unlock phone
option 4 will release you from restoring ball back.
phpone in future will work without this ball N1.
if anything is still not clear- please ask more