Open the file in Excel, then put whatever values you want in the 1st (fundamental), 2nd, 3rd, 4th...up to the 11th harmonic. Be sure to set the phase (in degrees) to whatever you wish. The spreadsheet is pre-programmed for a square wave, but you can play with it any way you like. The resulting Bullard plot follows your settings and displays the fundamental in the center of the plot, along with the resulting wave (depending on your DC offset) and spaces the harmonics out across the display. The one thing you may want to adjust yourself is cell Q2, which controls the gain of the harmonics. If the harmonics seem too small, gain them up, if they are too large gain them down. Your choice totally.