You can use TemplateMapper... It sets up a project to manage import from a new
template into a legacy book. You create map files that manage how to import
individual formats (turn LegacyBody into NewBody), and load legacy, template,
and map files into a project. The project can import pgf, char, table, xref
fprmats, plus cond text tags, master page usage, variable names, and ref page
usage. If you have a lot of importing to do, it might be the product for you.
You can see more about it at http://www.cudspan.net.