You must follow a specific procedure when modifying or removing Oracle Clusterware and Oracle Automatic Storage Management (Oracle ASM) software.

• Deciding When to Deinstall Oracle Clusterware
  There are certain situations in which you might be required to remove Oracle software.
• Migrating Standalone Grid Infrastructure Servers to a Cluster
  If you have an Oracle Database installation using Oracle Restart (an Oracle Grid Infrastructure installation for a standalone server), you can reconfigure that server as a cluster member node, then complete the following tasks.
• Changing the Oracle Grid Infrastructure Home Path
  After installing Oracle Grid Infrastructure for a cluster, you might need to change the location of the Grid home.
• Unconfiguring Oracle Clusterware Without Removing the Software
  By running rootcrs.bat -deconfig -force on nodes where you encounter an installation error, you can unconfigure Oracle Clusterware on those nodes, correct the cause of the error, and then run rootcrs.bat again to reconfigure Oracle Clusterware.
• Removing Oracle Clusterware and Oracle ASM Software
  The deinstall command removes Oracle Clusterware and Oracle ASM from your server.