Forstly: read out the existing settings and write them down somewhere

BMW Assist needs to be ticked to make that function work. Otherwise, it won't appear in the menu

Auto Emergency Call initiates an emergency call under certain situations eg a crash

SMSC centre is the switching centre that the sms messages are routed through. Your mobile phone provide can give you this number

The SMS number is the number of BMW Assist. Ask BMW in your country for that number