How do i move multiple tickets to a different department?

How do i move multiple tickets to a different department?

Hello, i have several tickets that have been assigned to the wrong department. 
I am talking about hundreds of automatically generated ones that come from a separate system.
How can i select them all at once to move them to another department in one go?

I can select them in "unsassigned open tickets view" but i can't find a "move to another department" option.
I also can't seem to assign multiple tickets to the same agent in that same view.

Could somebody advice?