Open the photo in your favorite photo editor (I'll use ), and select the Clone tool. In Elements, it's called the Clone Stamp Tool, and it's in the 15th cubby from the top of the toolbar.

You'll find a lot of controls in the Tool Options palette at the top of the screen, but only a few are important: the size of the brush, the opacity, and the Aligned checkbox. As a general rule, you'll want to set the brush to a size that's somewhat smaller than the object you're removing, but not so small that erasing it will take a lot of brushstrokes. As you use the tool, you'll get more comfortable estimating the right brush size. Most of the time you should set opacity at 100 percent, but for certain subjects--such as a boat on the ocean--you might start at 100 percent and then finish by painting a bit at a lower opacity to disguise any sharp edges that would give away the editing job. Finally, the Aligned checkbox determines whether every time you click to paint you get pixels from the source location, or from some distance away. For this photo, I'll leave it unaligned.

After you choose the brush size, it's time to pick the source in your photo. To do that, point the mouse where you want to sample from, and Alt-click. Some programs, such as , make this step a right-click.

Now it's time to paint. Click in the area you want to eliminate, and paint to overlay pixels from the source area of the painting. In this case, I chose a source area just above the sign and aligned with the left side of the building, so I could just paint downward and extend the building in a natural and realistic way.

As you go, you might need to change the source location. For example, to remove the signpost from in front of the bus, I reduced the size of the brush and set the source in various locations on the bus itself so that I could paint over the post with natural-looking textures. Here's how the final image turned out: