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