Erase parts of an image with the Magic Eraser tool

Select the Magic Eraser tool (E) from the toolbar. If you can’t find the tool, select and hold the Eraser tool to show the other related tools and then select the Magic Eraser tool.

Follow these steps in the options bar:

• Define the range of colors to be erased by entering a Tolerance value.
• Select Anti-aliased to smooth the edges.
• Select Contiguous to erase only the pixels contiguous to the one you select, and vice-versa. 
• Select Sample All Layers to sample the erased colors.
• Define the strength of the erasure by specifying Opacity.

Click the part of the layer you want to erase.