This is the 14031st most frequent Spanish word.
sustituirlo
"To replace it."
Here, 'sustituirlo' is used to mean replacing an item. It refers to an object that is being replaced, and the context suggests the object is damaged.
Necesitamos sustituirlo por uno nuevo porque está roto.
We need to replace it with a new one because it's broken.
In this case, 'sustituirlo' refers to replacing a person temporarily, indicating substitution during a specific period.
El profesor dijo que iba a sustituirlo durante su ausencia.
The teacher said he would replace him during his absence.
Here, 'sustituirlo' implies finding an alternative for an item or concept to fulfill a specific function or task when the original is unavailable.