We bought a property located in the city limits of Chicago - It is a grandfathered 2 flat located in B3-2 (Community shopping - destination oriented, no limit on size of commercial establishment. Allows dwelling units above ground floor. )

When we bought it is was partially converted to a SFH - so we went through hell with the appraisal. We would like to get the zoning changed to make it a legal SFH and complete the interior conversion (basically making the 2nd unit living/dining into bedrooms)

Does anybody know if I need an attorney or if I can just submit a zoning change request with the city? The only reason for the change is because we want it, do I have to prove it is "better for the community"

Any advice would be greatly appreciated.