What to know when replacing smartphone motherboard?

[j591]

Contemplating replacing my J5(SM-J9500Y) motherboard due to water damage. What do i need to know first when doing this?

 

[hallux]

Your IMEI number will change. You will lose any data that was on the old one. Be VERY gentle with the connectors.

 

[smvim]

Just wondering how much was your phone exposed to the water? ... and are you sure it's just the motherboard that was affected and not the display or some other components too?