How would a senior citizen file for bankruptcy in Indiana?

You really need a lawyer for this.

Can you explain why the senior citizen needs to file for bankruptcy?

A senior citizen files for bankruptcy the same way any person does.

I suggest this person go to several free consults with bankruptcy attorneys. Yes..they all do free initial consults. To make those consultations worthwhile..they need to bring all their financial records with them. Do not sign up with any lawyer...do at least 3 consults before making any decisions.

There are a couple of bankruptcy lawyers that run a website to offer help...bkforum.com. Maybe ask  questions there.