The best way to clear karmic debts is to make the self-effort to clean our mind. The present karma is the best way to clear the bad past karma.
Renunciation of sense objects, self-control, prayer, meditation, austerity in thought, word, and deed are some of the ways to make our present karma god.
Bad past karma are the result of our selfish thoughts and actions and it can be overcome by our selfless thoughts and actions in the present.
Only by such effort can we prepare ourselves to achieve direct perception and attain good karma to clear the old karmic debts.
We get what we deserve, and our deserving depends upon our doing.
Bad karma is cleansed through self-surrender. It is surrendering everything — our body, mind, and soul — to the Divine. This can happen only when we can see God in everything and everything in God. There is no discrimination. There is nothing to conquer. There is nothing to achieve.
Bearing all troubles and tribulations with humility is the real test of self surrender.