Double-click on the "Audacity" icon on your desktop. If you don't have a desktop shortcut, click "Start," "Programs" and select "Audacity." If you're using a Mac, you either can click the "Desktop" icon or open the program from the "Applications" menu.
Open the relevant session. When you open Audacity, the last recording you saved loads automatically. If the vocal is in this session, you don't need to do anything else. If it is another session, click "File," and select "Open Recent." Select the session from the drop-down menu.
Identify the vocal that you want to remove. Play the track, and "Solo" each vocal track by clicking the "S" icon on the respective channel strips to mute everything but the track you've soloed.
Click "File" and select "New Track." A new track automatically opens under the selected track. Click "M" on the new track to mute it. Double-click the channel name box, and type in a name for this channel. Select a name, such as "Bad Vocals," that indicates is a muted channel used to store unused audio.
Click "Edit," and select the "Scissors" tool. Click on the "Scissors" tool on either side of the part you want to remove on the bad vocal track. Use the sound wave graphic as a guide. Loud parts, such as opening lines, are represented by tall peaks. This separates the bad audio from the rest of the track, and makes it a new file.
Drag the snipped audio file onto the muted track to give you the option to use it again or fix it if you later change your mind. If you want to remove an entire vocal track, forgo the "Scissor" edit, and drag the entire audio file onto the muted audio track.