unconfigure disk if the disk is stuck at Veritas Volume manager

1) Run the following command to rename 'es_rcm.pl' script.
# mv /etc/rcm/scripts/es_rcm.pl /etc/rcm/scripts/DONTUSE
NOTE: VxVM 4.1 and above 'es_rcm.pl' script is under /usr/lib/rcm/scripts
# mv /usr/lib/rcm/scripts/es_rcm.pl /usr/lib/rcm/scripts/DONTUSE
2) Run "/usr/sbin/cfgadm -c unconfigure ......" again. This command will finish successfully.
Example:

# /usr/sbin/cfgadm -c unconfigure c0::dsk/c0t0d0
3) After that, rename back file "DONTUSE" to the original name.
# mv /etc/rcm/scripts/DONTUSE /etc/rcm/scripts/es_rcm.pl
NOTE: VxVM 4.1 and above 'es_rcm.pl' script is under /usr/lib/rcm/scripts
# mv /usr/lib/rcm/scripts/DONTUSE /usr/lib/rcm/scripts/es_rcm.pl
4) Then physically replace the failed boot disk with new one.
5) Run the following command.
# cfgadm -c configure c0::dsk/c0t0d0
6) Run VERITAS Volume Manager[TM]'s usual procedure.
# /usr/sbin/vxdctl enable