Rotate the Cloud KMS key version and continue using the same Cloud Storage bucket.

Create a new Cloud KMS key and set it as the default CMEK key on the existing Cloud Storage bucket.

Create a new Cloud KMS key and a new Cloud Storage bucket, then copy all objects from the old bucket to the new one specifying the new Cloud KMS key in the copy command.

Create a new Cloud KMS key and a new Cloud Storage bucket configured to use the new key as the default CMEK key, then copy all objects from the old bucket to the new bucket without specifying a key.