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Is there a way to bulk load the product backlog with stories and epics that already exist?
Accepted answer
You can run a query to show all the work items then do a bulk edit. This can be done in the web client or the eclipse client.
The fields you need to edit are the "planned for" and the "filed against" fields.
Very very detailed article on querying: https://jazz.net/library/article/1007/
Article that mentions bulk editing of work items: https://jazz.net/library/article/534/