Como modificar botão de reputação + / -

.vote {
padding: 4px 1px 4px 1px;
text-align: center;
width:20px;
background-color: #eaeaea;
border: 1px solid #d4d6d5;
-moz-border-radius: 5px 5px 5px 5px;
-webkit-border-top-left-radius:5px;
-webkit-border-bottom-left-radius:5px;
-webkit-border-top-right-radius:5px;
-webkit-border-bottom-right-radius:5px;
}

.vote .vote-no-bar {
display: none;
}

.vote .vote-bar {
border-left: 0px;
border-right: 0px;
border-top: 1px solid #ffffff;
border-bottom: 1px solid #d4d6d5;
font-size: 0px;
height: 50px;
margin: 0px;
width: 20px;
padding: 3px 0px 3px 0px;
}

.vote .vote-bar-plus {
margin-left: 7px;
width: 6px;
}

.vote .vote-bar-minus {
margin-left: 7px;
width: 6px;
}

.vote .vote-button a[href*="plus"] {
background: url('URL_DA_IMAGEM');
background-repeat: no-repeat;
color:transparent;
display:block;
height:21px;
width:22px;
}

.vote .vote-button a[href*="minus"] {
background-image: url('URL_DA_IMAGEM');
background-repeat: no-repeat;
color:transparent;
display:block;
height:21px;
width:22px;
}