Namaste. I have heard that doing meditation removes your past and present bad karma. Is that true? If so, how?
Paramhansa Yogananda did indeed say that meditation can overcome our karma. Here is how he put it (from The Essence of Self-Realization):
“An important factor in overcoming karma is meditation. Every time you meditate, your karma decreases, for at that time your energy is focused in the brain and burns up the old brain cells.
“After every deep meditation, you will find yourself becoming freer inside.”
He also emphasized that of particular help in this is the practice of Kriya Yoga, the advanced meditation technique that Paramhansa Yogananda taught. You can read more about that technique in his Autobiography of a Yogi as well as in Swami Kriyananda’s autobiography, The New Path.