Pages Layout, Different Top Margin on 1st Page, 3.0", remaining pages 1.0"

Creating a legal document. An Affidavit. The recorders require a 3" clear space at the top of the 1st page for recording information. i.e. State, County, Book #, Page #.

The remaining pages are normally 1.0" to 1.5".

Step by step instructions for an old man would be great. Thanks