RM 1.1 Reassign source

I know it's possible and I also know I've seen the control for it but now when I actually have a resource I'd like to reassign I cannot find the control for doing so. Can someone please point me in the right direction?:(
I don't get it.

I've set the administrator to be able to do everything everywhere and still there must be something missing. On another user accounts listing I have no permission at all to edit the resource!