Several states have a homestead credit, like Maryland and Wisconsin. Which state are you referring to? If you back out of your state return by going to the federal return, or continue to the end of it, you will have an option to review or edit the state return. You should see an option to delete the state return on that screen, you can do that and re-enter your state tax information and that will clear the homestead credit option you chose.
You can also simply go back through the state return and see if there is an option to delete the homestead credit in the section where you entered the information for it.