I missed mentioning that the query can also be written by excluding the FROM clause

UPDATEdbo.tblCust

SETLAST_NAME = SUBSTRING( FIRST_NAME, CHARINDEX( ' ', FIRST_NAME ) + 1, 100 ) + LAST_NAME,

FIRST_NAME = SUBSTRING( FIRST_NAME, 1, CHARINDEX( ' ', FIRST_NAME + ' ' ) - 1 )

WHEREFIRST_NAME LIKE '%-'

Terry, Sometimes I hit the keyboard faster than usual when I spill my coffee over it:-D