When it comes to the sacramental record, no, the Godparents cannot be changed. The reason for this is that the Godparents fulfilled a specific function at the baptism, no one else fulfilled that role. Godparents act as the official witnesses and sponsors at the baptism and it would be a lie to say that someone else acted in those roles.
When it comes to the social role of Godparents, you’re certainly free to invite people of faith and good character to play a special role in your child’s life.
