Things You'll Need
Instructions
Turn your home computer on and open up Adobe Photoshop, either the full-featured program or the consumer version known as Elements; both programs have the tools needed to complete this task.
Click "File" in the navigation bar and select "Open" from the drop-down menu. Use your computer's cursor to navigate to the folder containing the image you want to edit. Click on the file to highlight it, then click "OK" in the bottom right of the window to open the picture.
Click "Layer" and select "New Layer," then click "OK." Click on the layer thumbnail in the right margin. Click "Filter" in the navigation bar of the program and select "Liquify" from the "Distort" category. This will open up a new window in the program.
Adjust the value in the "Pen pressure" and "Pixels" to change the tool's strength. Increasing "Pixels" will create a large tool and will make it easier to reduce the size of the picture.
Position your computer's cursor in the area you want to adjust. Click and hold the mouse and run the cursor along the edge of the area you want to make thinner. The program will push the area inward. This is easily visible on the portions of your picture containing people.
Click "Layer" in the navigation bar and select "Flatten image" from the drop-down menu. Click "File" and select "Save as." Give your edited picture a new name or title and save it to your computer's hard drive.