1) Shutdown all datbases that are running on the box using the +ASM instance for storage management

2) Use emca -x <sid> to remove the Database Console for each instance

3) Remove the service for the instances

      ORADIM -DELETE -SID <sid> and ORADIM -DELETE -ASMSID <asm sid>

       to delete the services for the database(s)/instances

        If using RAC ... remove the asm service with .... svrctl remove asm -n <nodename>

3) Remove the PFILEs / SPFILEs and password files (orapw<sid>) for the ASM and Databases

       Default location: <ORACLE_HOME>/DATABASE

4) Delete / Remove any non ASM supporting directories

       BACKGROUND_DUMP_DEST
       USER_DUMP_DEST
       CORE_DUMP_DEST
       etc

5) Format the ASM disks