Reorganize Projects and Subprojects

I use GTD Outlook Addin and when I stared using it I spontaneously created Projects and Subprojects as they occured to me while adding the tasks.

But now I am finding that I have not structured it properly. I would like to reorganize my Project and Sub project structure. How do I do it? Note there are various mails of mine which are currently linked to tasks + subproject + project for varous GTD actions.
 
Top