Last week, Microsoft announced the ability to change work item types in VSTS. So if you create a Product Backlog Item, you can change it to a Bug. This came in handy today as I was entering a bug into VSTS, but I mistakenly entered it as a PBI.
You can open the Work item, then click on the Options elipsis on the top right, and select “Change type…”
Enter the new type and enter a reason, then click OK.
You get the opportunity to review your changes
Once I save, there is a history record of the change:
And my Kanban board reflects this change:
More info on MSDN: https://msdn.microsoft.com/en-us/library/vs/alm/work/backlogs/remove-delete-work-items#change-type