To update a stack set

The following update-stack-set example adds a tag with the key name Owner and a value of IT to the stack instances in the specified stack set.

aws cloudformation update-stack-set \
    --stack-set-name my-stack-set \
    --use-previous-template \
    --tags Key=Owner,Value=IT

Output:

{
    "OperationId": "e2b60321-6cab-xmpl-bde7-530c6f47950e"
}