Open your control panel and look for DB's Paths and URL's settings and you should see the Relative URL to Images Directory. This is your relative path an you should have an Avatars Folder inside that directory. Make sure you uploaded them inside the Avatars directory. Mine is UBBThreads/Images/Avatars/all go in here
How did you upload the new files? Make sure your permissions are correctly set for the new images if you used FTP
You should not have to change anything (path related)in avatars.php all paths are set in the control panel
Since the modification were only minor the only updating I will probably do will be adding more Avatars images
