Change to the advanced privilege level:

If the node is healthy, then at the advanced privilege level of a different node, use the cluster modify command with the -node and -eligibility parameters to mark it ineligible and isolate it from the cluster.

cluster1::*> cluster modify -node node2 -eligibility false

Use the system configuration recovery node restore command at the advanced privilege level to restore the node’s configuration from a configuration backup file.

cluster1::*> system configuration recovery node restore -backup cluster1.8hour.2011-02-22.18_15_00.7z

Warning: This command overwrites local configuration files with
         files contained in the specified backup file. Use this
         command only to recover from a disaster that resulted
         in the loss of the local configuration files.
         The node will reboot after restoring the local configuration.
Do you want to continue? {y|n}: y

If you marked the node ineligible, then use the system configuration recovery cluster sync command to mark the node as eligible and synchronize it with the cluster.

If you are operating in a SAN environment, use the system node reboot command to reboot the node and reestablish SAN quorum.