Separating family name from full name

Yes, but what format are the names in currently?

There are instructions at the top of the page explaining how to attach your sample workbook.

A good sample workbook has just 10-20 rows of representative data. It also has expected results mocked up, relevant cells highlighted and a few explanatory notes.

If the family name is always last:

=TRIM(RIGHT(SUBSTITUTE(A1," ",REPT(" ",99)),98))