How can I update the item Structure using the SOAP API

Summary:

I need to update the Existing Item Structure using the Soap API and Items are not under Change Order

Content (please ensure you mask any confidential information):

I need to update the Existing Item Structure using the Soap API and Items are not under Change Order

Version (include the version you are using, if applicable):

24D

Code Snippet (add any code snippets that support your topic, if applicable):