Want to insert a New image in an MP3 song, follow this steps:-
Open Windows Media Player in your PC.
Choose the image you want to put in your song.
Right-click on the image and press copy.
Go back to windows media player and Find the song in music library.
Right click on the song album and click past album art.
close windows media player and open the song by any other media player like VLC.
Some important points:-
the image you want to put in your song must be square in size.
after changing the original cover image it can not be restored.
Have Fun.