Obtain music files from a CD and transfer the files onto your computer using iTunes. Your Mac should come with iTunes already installed.
Insert the CD into the disk drive. Select the music files you wish to import by clicking the check box beside each file. Select “Import” in the iTunes window.
Navigate to the location where the music files were saved. Unless you have designated otherwise, they will have imported to your iTunes folder.
Open GarageBand and choose “Open” from the “File menu.” Navigate to where the MP3 tracks are saved and select the track you wish to edit.
Select the editing pane at the bottom of your screen.
Select sections of the song by holding down the cursor over a specific part and dragging it over the area.
Delete a highlighted area by pressing the “Delete” key on your keyboard. You can also click “Delete” from the “Edit” menu.
Move a highlighted area by right clicking and selecting “Cut,” then right click again and select "Paste" in the desired location on the editing pane. These commands can also be found in the “Edit” menu.
Select “Undo” from the “Edit” menu if you make an error to revert to a step before the error.
Save the edited music file in the desired location on your Macintosh.
Download and install the “SolveigMM WMP Trimmer” plug-in for Windows Media Player. This plug-in can be downloaded for free and allows users to edit music files. Download the software to your desktop and double click on the icon to begin installation. Follow the instructions on screen to install the plug-in.
Open the Windows Media Player software by navigating to the Start Menu and the “Programs” tab.
Click the “Tools” menu from the top main menu pane and select the “Plug-ins” option. Select “SolveigMM WMP Trimmer Plugin” from the options.
Open the desired music file by navigating to the “File menu” and clicking “Open.” Browse your computer and open the desired file.
Move the play-head on Windows Media Player to the location where you want the audio to begin. Select “Click to Start” to trim the file to the new starting position. Repeat the procedure to trim the end of the audio file by moving the end slider to the desired location. Select “Click to End.".
Click the “In” button to trim a selected interval. Select the “Out” button to cut a selected interval out of the music file.
Choose “Save” from the “File menu” in Windows Media Player and save the edited audio file in the desired location.