The migration tool, dsmig, is delivered with the Directory Server 6.3 packages. When these packages have been installed, dsmig is located in install-path/ds6/bin.
dsmig must be run on the machine on which the new Directory Server instance will be located. When the command is run, a migration directory is created within the new instance directory (new-instance-path/migration). This directory is a repository for data produced by the migration, including log files and migration status files.