I would recommend surgical excision to remove a flat, black mole on the nose. In essence, you would ideally be trading the mole for a thin, linear scar. In most cases, the scar would be less noticeable than the mole.
There are many options for treatment including shave removal with laser or dessication will give improvement. Scarring will be minimal and can be treated with lasers and microneedling. Best, Dr. Emer