I have a regular expression to find the text I want (I wrapped the relevant section in custom tags), and I can do it by hand without much issue, but what I want is a way to automatically find and replace throughout the entire project.
A macro seems like an OK idea, but it would be nice to have a command (to edit and tweak).
sed seems like a good bet, but I am pretty unfamiliar with it. I am not so much asking for a complete solution as I am asking for an example that does something close to what I want. I don't really know of a good way to start.