In a dark place, or at night, set two parallel rows of candles, width the space of your outstretched arm, for about 20 to 30 feet, about a foot between candles. they must be white candles, fresh and never used before. after the approximately 20 feet, make a circle of candles, with circumference the same as the width of your arms outstretched. the circle must be southernmost.
Light all the candles except a few between the "path" between rows. hold with you a white candle, lit, same as the others. you must also be wearing all white clothes. light the candles, and after doing so, kneel before the path, to the south, and ask for a blessing from the gods for your spell.
Walk with the lit candle slowly until you get to the circle, stepping over the unlit ones, turn, now facing the north, and light the candles that were unlit. (ideally 3 there) blow out the candle in your hands, and look at the smoke it makes, feeling your old eye color float away with it. you can sit or stand at this point, in whatever direction feels comfortable. Close your eyes, and feel with your spirit all the candles of the circle, and the path. focus the light in your eyes, and shift it to the color you want your eyes. when you feel the color staying, and a feeling of completeness, open your eyes. blow out the 3 candles to your north, and exit the circle.
Use the candle that you walked with to relight the 3 candles, and blow it out once more. walk down the path feeling the power around you, until you get out of the path. kneel once more to the south, and thank the gods for their attendance, and one by one, in the order you lit them, extinguish the candles.