As of January 1, 2018 the regulations for changing the gender on a birth certificate has changed for the better. This applies to all transgender individuals who were born in the State of Illinois. Surgery is no longer a requirement to be able to change the gender on a birth certificate. The process for name change on a birth certificate is still the same. Below, is the website for the Illinois Department of Vital Records for name change and gender change. Forms in PDF for name and gender marker change are also on this page for download! Instructions for the forms are in the download and also advise how to do name change along with gender marker change if it was not done and needs to be.
Illinois Department of Vital Records: http://dph.illinois.gov/topics-services/birth-death-other-records/birth-records/gender-reassignment