1 drop diskgroup DATA including contents;

2 drop diskgroup FLA including contents;

3 srvctl remove diskgroup -g DATA

4 srvctl remove diskgroup -g FLA

5 srvctl remove asm

6 Remove the directory of $ORACLE_BASE/admin/+ASM

7 vi /etc/oratab

--remove this line--
+ASM:/opt/oracle/product/10.2.0/db_1:N

[@more@]