You would need to either delete or more likely add real property and insert its location and value on Schedule A. You would need to find the applicable exemption protecting whatever equity you might have in that property on Schedule C.
You will need to look at your local bankruptcy court rules for guidance. The rules should be posted on the court's website - not on Pacer.
The amendment part is to simply resubmit the Schedules to include the missing information. You should indicate in the title that the schedule is "amended."
Some communities require an amendment cover sheet, which may be posted on the court website. If no cover sheet is required, you must attach a statement to indicate that you are certifying that the amended schedules are truthful & that you are signing them "under penalty of perjury."
Hope this perspective helps!
If you need to amend schedule A, you must have left out some real estate. That's an important omission. And if you need to amend schedule C, you need to claim an exemption. That's an important legal right. You may not know enough to handle this right yourself. And the exemptions you claim may vary depending on where you have lived for the past two years.
You may need legal counsel. Here in Chicago, you can check with the "Help Desk" at the 6th floor of the Dirksen Federal Building. You may get enough help there. Otherwise, it might serve your interest to seek the assistance of an attorney.