How to remove 11gR2 grid infrastructure.

go to :- grid install home/deinstall/

host(+ASM) /cbb09/u0001/oracle/product/11.2.0/grid_1/deinstall
>./deinstall
Checking for required files and bootstrapping ...
Please wait ...
Location of logs /cbb09/u0001/oracle/oraInventory/logs/

############ ORACLE DEINSTALL & DECONFIG TOOL START ############


######################### CHECK OPERATION START #########################
Install check configuration START


Checking for existence of the Oracle home location /cbb09/u0001/oracle/product/11.2.0/grid_1
Oracle Home type selected for de-install is: SIHA
Oracle Base selected for de-install is: /cbb09/u0001/oracle
Checking for existence of central inventory location /cbb09/u0001/oracle/oraInventory
Checking for existence of the Oracle Grid Infrastructure home /cbb09/u0001/oracle/product/11.2.0/grid

Install check configuration END

Skipping Windows and .NET products configuration check

Checking Windows and .NET products configuration END

Traces log file: /cbb09/u0001/oracle/oraInventory/logs//crsdc.log

Network Configuration check config START

Network de-configuration trace file location: /cbb09/u0001/oracle/oraInventory/logs/netdc_check2011-01-04_02-55-17-PM.log

Network Configuration check config END

Asm Check Configuration START

ASM de-configuration trace file location: /cbb09/u0001/oracle/oraInventory/logs/asmcadc_check2011-01-04_02-55-19-PM.log