After you delete the instance, you can begin the process of deleting the node from the cluster. You accomplish this by running scripts on the node you want to delete to remove the Oracle Clusterware installation and you run scripts on the remaining nodes to update the node list.
See Also:
Oracle Clusterware Administration and Deployment Guide for information about deleting nodes from the cluster
Oracle Grid Infrastructure Installation Guide for Microsoft Windows x64 (64-Bit) for more information about removing Oracle Clusterware and Oracle ASM