Feel free to use which ever imaging editor your prefer. The avatar size requirement is 155px x 75px. The below example uses a simple free web-based imaging editor.

Go to: SnipShot

Upload you photo

Once it’s uploaded go to ‘Adjust’ in the header of the page. Once it’s selected it will turn green and you’ll get a window like this:

Next, lets set the image width and height:

Be sure click the ‘lock’ symbol in between W _ px & H _ px, so that it’s off. Also, enter 155 x 75. Once you’ve made all the changes you want, click save. Save to where ever you’d like on your computer, then upload to ‘Forum Profile’ / ‘My Avatar’ on our site.

Hope that helps. :)

There’s many other online editors, and applications you can use. I just found this one, tested it, seems to work fine and is very easy to use.