How can one repent from working for an interest-based bank for 20 years?

Repentance from working in a usurious bank necessitates leaving it immediately, regretting past actions, and resolving not to return. As for the money earned, scholars have three opinions: The first is the obligation to dispose of all of it. The second is the permissibility of taking from it for sustenance if one is poor, while disposing of the excess. The third is that there is no obligation to dispose of any of it. The fatwa issued adheres to the second opinion.