I’ll explain it to him
I'll explain it to him.
Si me deja entrar, se lo explicaré.
If he lets me in, I’ll explain it to him.
— Suspiria: Alarido (1977)
I'll explain it to you.
Se lo explicaré mediante un ejemplo.
I will explain it to you with an example.
— Brigadas rojas (2008)
Pues lo va a pensar en mi oficina y se lo explicaré en privado.
Well, he'll think about it in my office and I'll explain it to him privately.
— Dos son familia (2016)
I’ll explain it to him/her later.
I'll explain everything to you.
I'll explain it to her.