Find and replace across line breaks

Trying to clean up some ebooks that break in my reader*.

How do I search and replace for something like this in the HTML?

That is, two tags that appear across line breaks.

thanks!



* I know two BR tags will effectively give me a paragraph break (I've fixed the real bits in the files that was borking the ebook) but it offends the OCD HTML tidy-er-upper that I used to be in my old job.