This is an insanely difficult project. If you want to replace any part from the logic board, your best bet is to replace everything.
Changing any one thing (SoC, connector, etc) isn't possible because you'd have to be really good as OS hacking to add support for it, especially when it is closed sourced.
Changing any one thing (SoC, connector, etc) isn't possible because you'd have to be really good as OS hacking to add support for it, especially when it is closed sourced.