Run them as SYS or INTERNAL (they are a kind of synonymous account, but INTERNAL will not be supported in future releases any more), either in SQL*Plus or in svmgrl (as a matter of fact, you can run catdbsyn.sql also as SYSTEM or any DBA user, but it is simplier if you run all of them as SYS or INTERNAL).

Do *not* run those scripts as SYSTEM. This is true also for catalog.sql, catproc.sql and catexp.sql, do not follow Halo's advice to run them as SYSTEM - they should be run as SYS or INTERNAL.

BTW, if you are in doubt you can allways open each of those scripts in text editor and in the header you'll usualy find the instrunctions on how and under each account the script should be run.

HTH,