Batch-changing resource templates question

Hello, knowledgeable ones...

The problem I have is: I'm about the third fellow to try building this website (in Evo 1.0.4 ATM); a large part of it is a web archive of a weekly publication. Every week, there's a letters page; on the resource tree, this means we have

Index >> issue number >> "Letters" >> Letter 1, Letter 2, Letter 3 etc (as separate resources)

So the obvious way to display them as one long batch would be to have a ditto call on the parent page (the middle point above, whose 'siblings' are the articles proper). So far, so simple.

The problem is that all the letter parent pages are set to a blank template; and, given the resource tree structure, there's no easy way to get all the document IDs lined up in Doc Manager. What I want to know is:

Is there any way to change all documents with Template X into documents with Template Y?
OR
Is there a way to change the template on all documents with a certain title (they're all called "Letters")?

Or Am I going through 500 odd pages doing it by hand? :-(

I would make a quick SQL update query to run on your hosting control panel's MySQL client (phpMyAdmin?) to change the template in the database. Are these the only resources with a template of 0? If so, the "WHERE ... " clause in the query could use that, or else it could use "WHERE pagetitle = 'Letters'"

Cheers - will get the server monkeys to give it a go.