Hi,

To install JVM,

run initjvm.sql script in $ORACLE_HOME/javavm/install directory.
you have many other scripts in the same directory connected with java.

To check whether its installed properly

SELECT Count(1)
FROM dba_objects
WHERE object_type Like '%JAVA%';

this query will return more than 4000 rows,

To remove JVM run rmjvm.sql

HTH

Srini