You need to install Oracle 9i in new oracle_home. Then restore your 8i database under the 9i home. There is a upgrade scripts in folder oracle_home/rdbms/admin called u0801070.sql, u0800060.sql. In then header of those files you have explanation how to use it. Run script under your new oracle_home. Also, you can use Database Upgrade Assistant to migrate your database.
I've been an Oracle DBA for 10 years and I have found that it is 10 times easier and safer in my humble opinion to do a full database export and a full database import. Plus, you get the benefit of cleaning up all the fragmentation in your database.
1. Full database export from 8i using the exp utility
2. Create a new 9i database and recreate the same tablespaces of about the same size.
3. Full database import from the 8i dump file using the imp utility
I would also suggest on the import using the INDEXES=N parameter, then using the INDEXFILE parameter through the imp utility to create yourself a sql script to rebuild all the indexes manually after the import has completed...