Notepad++ is my favourite text editor. It’s incomparably more powerful in feature-rich than Windows Notepad, however, even Notepad++ can’t do proper multi-line search and replace out of the box.
Sure, you can enable the Extended search mode and mark each new line with \n, but this is clunky and only practical if you have only a few lines of text to replace.
For anything bigger, I’d suggest installing the ToolBucket plugin (Plugins > Plugins Admin). After it’s installed, click on Plugins > ToolBucket > Multiline find and replace.
Couldn’t be any simpler…
Windows 10 Pro (22H2)