You don't.
Column width and row height is a property of the entire column and row.
Several workarounds if just for appearance.
Copy your lower data to a new sheet.
Adjust your column width.
Take a picture of your range using SHIFT + Edit and copy picture or use the
Camera Tool to take a picture.
Paste below the upper range on sheet1.
OR
Use the Center Across Selection format from Format>Cells>Alignment.
Gord Dibben MS Excel MVP