How do I go about filing bankruptcy if I am disabled and get SSI since 2009?

Much the same way as if you were not disabled and on SSI. That is, try to find an experienced lawyer who will offer you a reduced rate, or permit payment in installments. (Your State Bar may have a lawyer referral service. Or if you live in Madison you could call Community Justice, Inc. at 204.9642 between 1 pm and 4 pm Mon. through Thursday.) It is possible to file a Chapter 7, old fashioned straight bankruptcy without a lawyer, but it is really not advisable: the forms get somewhat complicated, and you could find yourself having to amend them time and again.

Based on the information you provided, I think you do not need to file bankruptcy at all. Some simple asset protection strategies could easily save you the time and trouble of going through bankruptcy.