Toggle links are normal hyperlinks so editing the links is basically just the same as editing any other kind of hyperlink. They can also be copied and moved in the same way as normal text. The toggle content in expanding section toggles is just normal text in a single-cell table and can be edited normally. Note, however, that you must move the link and table of expanding text toggles together! They will not work if you separate them.
The text of inline text toggles is stored in the Edit Toggle dialog and can be edited by double-clicking on the toggle link.
Expanding image toggles can be edited by double-clicking on them.