What is the expiation for one who commits a major sin?

Allah Almighty expiates major sins through sincere repentance, which involves abandoning the sin, regretting it, and resolving not to return to it, along along with fulfilling the rights of others if they exist. Allah accepts repentance from the disbeliever and the sinner, and He does not close the door of repentance to any of His creation, not even hypocrites if they repent and mend their ways.