You can add a negative margin to the pseudo-element or use it position: absolute.
Absolute Position: http://jsfiddle.net/ZwYyL/6/
.list-icon-pros {
list-style: none;
padding-left: 20px;
position: relative;
}
.list-icon-pros li:before {
font-family: FontAwesome;
color: #B3B300;
content:"\f00c";
position: absolute;
left: 0;
}
Negative field: http://jsfiddle.net/ZwYyL/5/
.list-icon-pros {
list-style: none;
padding-left: 22px;
}
.list-icon-pros li:before {
font-family: FontAwesome;
color: #B3B300;
content:"\f00c";
margin:0 5px 0 -22px;
}