Knowing we should and knowing how are two very different things.
Forgiving is not something we do. Forgiving is how when automatically become, a gift, as we become God conscious-- not 'self conscious' but God conscious.
(Please beware of spurious "meditations" and hypo-conscious techniques that place you into a state of "Self-consciousness" instead of God consciousness. "Self consciousness" mimics "God consciousness" and is an altered state that can seem like mediation, but is really very much the opposite. God Consciousness and “Self consciousness” are two very different things, It is vital that you learn to meditate safely.)