welcome to the notepad++ community, @Morney-le-Roux
you need to install the plugin HTML Tag, by using the built in plugins admin on newer versions of notepad++, or using the old plugin manager, if you are on notepad++ 7.5.9 or below.
once installed, select your partial or complete text, like “ADAMS, Andr\u00e9as” and go to plugins > html tag > decode js, to get “ADAMS, Andréas”.
best regards.