Open the music creation program or download a free trial version online. Import the stereo MP3 by selecting "File" from the top menu, then "Import."
Click "Track Properties," located to the left of the song. Expand the "Track Window" to display the audio waves. Right-click the song, then select "Add Effects" from the side menu. Click "De-Noise" from the list of options and wait as the effect loads.
Highlight an end portion of the song, then right-click and select "Add Effects." Select "Echo" from the side menu, then set the "Echo" parameters according to your choice.
Scroll back to the beginning of the song and highlight a portion of it. Right-click and select "Add Fade" from the side drop-down menu. In the "Timeline" field, type in the time you want the "Fade" to start in the song.
Add additional effects to the song by following the aforementioned steps. Save the song to your computer by selecting "File" from the top menu, then "Save."