If your UFT manual does not have reference to importing from ROOTS III on those pages (Premier versions or later) you may find it necessary to read parts of the manual provided on the distribution CD-ROM.
Another source of this information is in UFT Help under Importing - ROOTS III Import. Again, be sure to read the notes! If you are opening UFT for the first time, choose to open an existing project, then navigate to the UFT\Sample\Kennedy.pro project; this will enable you to get to the help system.