Click the "Audio Regions List" title at the top of the column on the right side of Pro Tools.
Choose "Import Audio" from the submenu that opens.
Browse through the files on your computer to choose the instrumental you want to add to your Pro Tools LE session.
Click "Copy" and then click "Done."
Select the "Audio Files" folder as your saving destination and the instrumental will appear in the audio bin.
Create a new audio track in the "Edit" window.
Drag the instrumental from the audio bin and drop it into this audio track (See References 1).