Question: As a previous result of a bad TFS project management, several tasks has been created in the wrong work item. Now I need to move several tasks to different work items. Is there an easy way to do it?

So far, I have to edit each task, remove the previos link to primary element and create a new one, but this is taking a lot of my time.

Answer: 
I suspect that the easiest way to do it would be from Excel. Create a Tree-based query that shows everything, then move the child records in Excel using simple cut and insert cut cells. Excel will then allow you to publish the new structure in one go.

If you need to move items up to a higher or lower level, place the Title Field in the column representing the level.

[See this little video I captured to show how it is done.](https://www.youtube.com/watch?v=86-8cb4LhS8&hd=1)
MS Project is extremely good with modifying hierarchies of work items. The steps are exactly the same as setting it up in Excel, but project inherently handles parent/child relationships, giving them a drag-and-drop interaction.

jessehouwing's Excel answer will be easier if you have never worked with project before.

**Updated** jesshouwing's comments are correct. Especially about the shivers.