You may need to shorten an MP3 file to customize it to your liking. If you have an MP3 song that needs to be edited, you can do so using some free audio software. As a Mac user, you can use iTunes, which comes with your computer, to edit the length of any MP3. As a Windows user, you can download iTunes or use another free audio editor, such as Audacity and MP3 Direct Cut.
Launch iTunes on your computer. Then click the "Library" button in the upper-left corner to display all MP3s in your music library.
Find the MP3 file you want to edit. Then right-click it and select "Get Info."
Click the "Options" tab across the top of the dialogue pop-up box.
Click both check boxes next to "Start Time" and "Stop Time."
Enter the start time and end time in minutes and seconds. For example, if you want to edit the MP3 to contain only the first 30 seconds of a song, enter "0:00" for the start time and "0:30" for the end time
Click the "OK" button and the new file is created.
Launch Audacity and import the MP3 file you want to edit. Click "File" and then "Open." Choose the MP3 file from your computer.
Click on the audio track displayed in Audacity.
Select a part of the MP3 file you want to keep. Simply click a start point in the track and use your mouse to drag the selection marker.
Click "Edit" and then "Trim." Your selection is now the only thing displayed in Audacity.
Click "File" and then "Save" to save your newly created MP3 file.
MP3 Direct Cut
Launch MP3 Direct Cut and open the MP3 file you want to edit. Click "File" and then "Open" to choose an MP3 file.
Select the section of the MP3 file that you don't want to include in the edited MP3 file. To select a section of the file, simply click inside of the audio track and drag your mouse.
Click the "Cut" button in the lower-left corner of the application. Repeat Steps 2 and 3 for any other sections of the MP3 track you want to cut or remove.
Click "File" and then "Save." Rename the file and save it.