This is the 1930th most frequent French word.
remplacer
To replace.
In this sentence, 'remplacer' is used in the context of substituting one object (the old phone) with another (a new model).
Je vais remplacer mon vieux téléphone par un nouveau modèle.
I will replace my old phone with a new model.
Here, 'remplacer' signifies the act of swapping out a non-functional item (the batteries) for a functional one.
Nous devons remplacer les batteries usées pour que l'appareil fonctionne.
We need to replace the worn-out batteries for the device to work.
In this context, 'remplacer' is utilized to mean taking over the responsibilities or role of someone temporarily.