Editing all instances of a string in Notepad++
Solution 1:
CTRL+H to get to the Replace dialog (or Search ==> Replace via the menu).
Input the string to find and input the string to replace it with and then hit the 'replace all' button on the right.
Solution 2:
You can also use Notepad++'s Mutli-Editing feature to do this inline.
https://notepad-plus-plus.org/features/multi-editing.html