Today I had someone ask about their past life and how to heal the karma. They knew they had been a magician in a past life that harmed others. The people they had harmed were dead so how could they heal the problems.
I always suggest karma yoga. It is a type of yoga that makes a spiritual practice out of doing charity and not expecting anything for it. No money or payment of any kind may be accepted. I feel that this could help quite a few people with bad karma in this life time also.
An act of charity and kindness will aid the community, aid the person and make it so this earth is a better place. A good example of this is the person doing dishes for a mission. Another person who contributes and helps passes out food for a food bank.
The list could go on and on. Yet the important thing is that the person does this and accept no rewards. It uplifts the persons spirit and show they are making an effort to be a different sort of person. It is the best way to turn bad luck and karma around.