Open your preferred digital audio workstation, for example Cubase, Mixcraft or Logic. It may take a few seconds for the program to fully load.
Click "File" and select "New." This opens a blank session. When prompted, name the session.
Click "File" again and select "Audio Track." This opens an audio track channel strip, with gain and pan controls.
Double-click where it says "Audio 1" and name the audio "Soccer Audio."
Click "File" and select "Import Audio." Browse for the audio file containing the vuvuzela noise that you want to remove. Once you find it, double-click or select "Open" to open it in the digital audio workstation interface.
Click on the track. This assigns subsequent edits to that particular track, rather than globally to any other audio you may add, such as voice over or sound effects.
Click "Tools" and select "Equalizer." An equalizer interface will open in a new window. An equalizer is a frequency filter that lets you boost and cut frequencies by band. Although each program's interface differs slightly, the basic interface and parameters are broadly similar; typically containing a spectrum analyzer and arrangement of slider dials, one per frequency band.
Play the audio so you can hear the changes in real time.
Click on the slider dial governing the frequency band containing 300Hz and drag it the bottom. The majority of the vuvuzela sound is on this frequency. This action mutes that particular frequency. This won't completely remove the sound of the horn, but it will diminish it slightly.
Click on the spectrum analyzer. This is the grid interface with the curve. The vertical axis represents volume and the horizontal axis represents frequency. Click on the curve and drag it around the grid. The dialog box the side tells you what the frequency is at any given moment.
Listen carefully to the remaining sound horns in the background. You'll notice certain sounds peaking as you boost them with analyzer. As soon as the vuvuzela peaks, stop moving the curve. Note the frequency band in the dialog box. This is the offending frequency. Reduce the frequency using the slider dials on the equalizer interface.