• photoshop
  
• a picture

First open your photo on photoshop by going to your upper right hand corner and selecting File and then clicking Open. Look for your picture and open.

Once you have your picture, make sure you have the window "Layers" open. If not go up and click the tab "Windows" and click on the "Layers."

Now look at that window and make sure you are on layers and not the other tabs, such as channels or paths. When on layers, look down at the bottom and you'll see seven more tabs, all with different designs on them. Click on the tab with the circle design. Half of the circle is dark and other is light. Should be the fourth tab from the left.

Click on that tab and then click on curves. Another window will pop up. now click on the line and move the line around. Moving the line up will make your picture brighter, moving it down will make your picture darker.

Another option is, instead of clicking curves, click on brightness/contrast. This will also allow you to make your picture brighter or darker.