Change certain text throughout the whole website at once using functions.php?

Hi,

May I ask for your help please? Stranger things have happened…

One of my clients, who has three Enfold based websites, wants to change the corresponding text where visitors can subscribe for her newsletter. The thing is, this text (+ subscription form Enfold MailChimp) is being used all over her three websites on almost every page and portfolio… :-(

The text now is “Aanmelden voor berichten over Landschappen voor de ziel” and she wants it to be “Aanmelden voor groeten uit het landschap van de ziel”.

Is it possible to use a certain code through functions.php to change this text to a new text throughout the whole website at once? That would be genius :-)

Thanks in advance & regards,
Monique