Load document based on ECS clipid into s3 using REST API?

Now our storage has been migrated to EMC ECS (from centera) and we have to use S3 as the connection method to retrieve document from ECS and upload it in S3.

How can we retrieve a document by passing ClipID to ECS and get the document uploaded in S3.

Rest API: _http://doc.isilon.com/ECS/3.2/DataAccessGuide/index.html#ecs_c_docs_landing_page_content.html

Many thanks,

KarlaP