Open your preferred digital audio workstation, or "DAW," for example Mixcraft 4 or Logic. The last saved session opens automatically. If this isn't the session for remixing, click "File" and select "Open Recent." When prompted, close the other session to minimize demand on your computer.
Open the "Mixer" window. DAW typically has two edit interfaces, one for arranging and one for mixing. Both have different control parameters and layouts to make the particular application more intuitive. The method for opening the mixer window varies according to which program you use but is rarely more than a two-click operation. For example, in Logic, click "Mixer" at the bottom-left of the screen. The mixer interface features a series of gain slider dials, each assigned to a particular frequency band.
Press "Play" so you can hear your adjustments in real time.
Tweak the gain slider dials for each audio channel. Start with the vocal channels. Move the slider dial up to increase volume, and move it down to reduce the volume. Aim for a balance of volume where the vocals are the most audible, but don't over-dominate the mix. If the volume-units meter for a particular audio channel flashes red at any point, the gain is too high.
Pan the stereo instruments right and left. If you have any stereo pairs, for example two identical guitar tracks, turn the "Pan" dial for one fully right and the "Pan" dial for the other fully left. The dial is typically above the gain dial. This creates a wider stereo image.
Click "S" to solo each channel, this mutes all other audio and lets you hear the selected audio in isolation. Tweak the parametric equalizer dials for each channel, starting with the channel farthest left. These dials govern the prominence of the bass, middle and high frequencies. Make adjustments to enhance the tonal properties of each audio channel. For example, reduce the bass in the backing vocal tracks to prevent them from sounding "muddy." (See Reference 2)
Leave the room for an hour to give your ears a rest. When you return, listen to the remixed audio at a variety of volumes. Make a series of final tweaks, then click "Save."