Juice the lemons
Remove any pulp and seeds from the juice
Set aside in the refrigerator
Place the lilacs in a bowl of cold water (just enough to cover)
Leave them overnight in the refrigerator
Heat 1 cup of water and the sugar in a small saucepan until the sugar is fully integrated.
Cool
Slice the lemon however you wish, and place it in the pitcher
Add the remaining ingredients (lilac, lemon juice, sugar syrup, and water.
Put ice cubes in cups and pour out.