It’s actually quite simple! The standard un-tarring SSH line is:
{code}
tar -xzvf your-tar-ball.tgz
{/code}
You can target a specific file or folder by adding another parameter:
{code}
tar -zvxf your-tar-ball.tgz your-folder
tar -zvxf your-tar-ball.tgz your-folder/subfolder/image.jpg
{/code}
Note: The process will go through the entire tarball, so be patient!