How to specify fillrate after pg_restore?

Hello,

I've been reading previous posts and I think I have some tables in my
database that would better be stored with fillfactor=90 or less. We are
going to upgrade and reinstall our server soon. I thought this would be
a good time to change fillfactor. Just I don't know how. First I need to
dump the old database with pg_dump. Then I need to restore it on the new
server with pg_restore.

What will this do?

ALTER TABLE tbl SET FILLFACTOR = 90;

Will it restucture the table, or is it just a setting and I should
perform a VACUUM to actually reach fillfactor=90?

Thanks,

  Laszlo