If you're doing it offline, it's as easy as OperaGhost said. Or you can even cut and paste from one data table to another. Even if you have code using the tags, won't matter that after the cut your code won't compile because of the lack of tags: the paste will remedy that.
If online and if the tags are used in code, then you should probably rename all the tags you want (I usually add 'XXX' to the end), create the Controller-scoped tags with the right name, then cross-reference each XXX local-scoped tag, and edit the XXX back out on the rung so that the logic now points to the correct tag.