Go to your local scoped tags, select the edit tab at the bottom of the window. Select the tag you want to move. Copy with CTRL+C
Go to your controller scoped tags, select the edit tab at the bottom of the window. Select the last row (empty "cell") and paste it with CTRL+V
Go back to your local scope tag and delete the tag.
You can probably save a step by using cut/paste, but if anything goes wrong while pasting, I don't think you can undo it.
Of course, the above description is when offline.