Visit your profile. Directly under your photo (avatar) is a list of options. The second option – "change photo". Click on it with the left mouse button once and you will see a list of options for adjusting photos. Select "upload new" and click once with the left mouse button. You see a window to upload photos.
Clicking the "browse" button, you will get the opportunity in the new window that opens to select the photo from your computer. Once a new avatar is selected – click on it then click "open". You get the window "edit a small copy". With it, select the image to be presented on the reduced copy of your avatar in the friends list, discussions, and more. To do this, drag the square box on the picture. Then click "save" and your page will update the main photo.
You can update your avatar in a different way, using pictures uploaded to your albums. Go to your photo albums (or found in the column to the left of the avatars link "my photos", or finding "my albums" under friends list). Select the desired photo album and then the photo.
Lower right under the image in the list of options find "to put on my page". Click on it once. On pictures added frame editing which you select the desired area of the photo that will become your avatar. To do this, move the squares in the corners and on the edges of the frame, clicking on them left mouse button.
After editing, click on the top right of pictures "done" button, and open your page with a new main picture. Otherwise, click "cancel" if the chosen image is something you are not satisfied.