The History Brush tool allows you to restore parts of an image to an earlier history state by painting over them.
Photoshop History Brush Tool
  1. Choose Window > History to open the History panel.  

  2. In the History panel, click the far-left column of the state that you want to use as the source for the History Brush tool. A brush icon will appear next to the selected history state.

  3. Select the History Brush tool (Y)

  4. Use the Options bar to customize tool settings, like Size and Hardness, to get the effect you want.

  5. Drag over the parts of the image you want to restore.