gistamin on "[Theme: Montezuma] How to change menu icon?"

I tried to do as it's written in Using Menu Icons but nothing to change.

/* Part 1- for default state: */
#menu1 .item-?p=5 > a > i { background-position: 0px 0px; }
#menu1 .item-?p=10 > a > i { background-position: 0px -24px; }
#menu1 .item-?p=138 > a > i { background-position: 0px -48px; }
#menu1 .item-?p=141 > a > i { background-position: 0px -72px; }