Once you have opened an image you can crop it to eliminate certain parts.

1. Choose the Crop tool from the Tools toolbar and drag out a crop selection around the area you want to keep. 
2. Start at one corner and drag to the other. Once you release the mouse button, you can adjust the selection rectangle by dragging its edges or corners, or from the center to move it.
3. Once you’ve selected the correct area, double-click within the selection rectangle to complete the cropping.