Make your way until you reach the room Sun Heart; once you're there, say Cleanse curse. You will be confronted.

Reveal that you need help.

You will get the following pop-ups:

1. 'Hahaha... so the great one returns to me, does he master?'
2. 'Got yourself into a spot of trouble, so you come running back to me?'
3. 'Yes, from this level of 'life' I can see into your soul, I can see your soul is not pure'
4. 'I take it you want me to help you again, after what you did to me?'
5. 'Well, do you really want me to help you? You know it will cost you greatly.

Choose 'YES' and your old alignment will be removed and you will permanently lose 10,000 vita and 5,000 mana.

Now you can go align at a different shrine or stay unaligned.