Go to your authors page.
At the main menu http://literotica.com/
click Stories & Pics
Then at the top it may say you are logged in as StrongMaster7 or it may say login into your profile.
If you are already logged in, click on your user name.
If you aren't logged in, login and them click on your user name.
Once you authors page is displayed click on the Profile link under Main.
Your profile will display. Scroll down to the bottom and replace the picture found there.
You could use this one if you like...
Right click on the picture and save as to you disk. Then click Chose File and find the pic you just saved.