Connect the microphone to the digital voice processor. Popular models of processor for live use are the BOSS VE-20, the TC-Helicon VoiceLive Touch and the Vocalist Live 3. Studio users may prefer rack mountable units like the TC-Helicon VoiceWorks Plus.
Choose a preset that raises the pitch of your voice. Raising a full octave will often be enough to change the sound of a man's voice to female, particularly when mixed with the natural voice. On some processors there may be presets specifically for male-to-female voice changes. See the documents that comes with your processor.
Adjust equalization to enhance the female effect. Cutting frequencies below 200 hertz while giving a slight boost around 250 to 300 hertz may make the processed voice sound more feminine. Male vocals sometimes have pronounced nasal tones that help identify gender. These may be altered with a parametric equalizer, if one is available.