After upgrade cleanup

Greetings, one and all,

I just did an upgrade from 8.1 to 8.2.3. We'll go up to 8.3.3 very
soon, but for reasons I won't go into, this intermediate step was
necessary. My problem is, now that the upgrade is done, how can I
clean up the database from the old version. I leave the original
database up as long as I can when I do an upgrade just in case I need
to revert to it. Now I have the databases from two versions on my
server and I need to get rid of the old one. Can I just remove the
old files from the data directories? With other systems, I've had
trouble removing database files because upgrades use certain files
from old versions. I don't want to break my new database. I'm on
Solaris 10.

Thanks,

Carol