You cannot turn off Find My without entering your Apple ID password. The option to turn off Find My is disabled if stolen device protection is enabled.
If you can get the PIN (shoulder surfing, social engineering) you can reset/change the Apple ID password.
Reportedly then you can add a second face to Face ID with Set Up Alternate Appearance and get access to everything, but I have not seen that confirmed.
Reportedly then you can add a second face to Face ID with Set Up Alternate Appearance and get access to everything, but I have not seen that confirmed.