Move Subsite from one parent site to another parent site

Hello,

   I need to move a subsite from one parent site to another site all within the same SiteCollection:

SiteCollection

-------->Child 1

-------->Child 2------->GrandChild1

Required

-------->Child 1------->GrandChild1

-------->Child 2

Everything could stay the same if I could change the Navigation in the Top Link Bar so that the dropdown changed from one subsite to another, but I do not think this is possible.

Thanks