수량버튼을 + - 가 양옆에 나오게 하고 싶은대요...

도대체 어디를 변경해야 하는지 ㅜ.ㅜ

버튼을 증가, 감소 대신 + -아이콘으로 바꾸려면 어떻게 해야 하나요??

도와주세요ㅜ.ㅜ

          <?php if ($is_orderable) { ?>
          <!-- 선택된 옵션 시작 { -->
          <section id="sit_sel_option">
           <?php
           if(!$option_item) {
            if(!$it['it_buy_min_qty'])
             $it['it_buy_min_qty'] = 1;
           ?>
           <ul id="sit_opt_added">
            <li class="sit_opt_list">
                <input type="hidden" name="io_type[<?php echo $it_id; ?>][]" value="0">
             <input type="hidden" name="io_id[<?php echo $it_id; ?>][]" value="">
             <input type="hidden" name="io_value[<?php echo $it_id; ?>][]" value="<?php echo $it['it_name']; ?>">
             <input type="hidden" class="io_price" value="0">
             <input type="hidden" class="io_stock" value="<?php echo $it['it_stock_qty']; ?>">
             <span class="sit_opt_subj"><?php echo $it['it_name']; ?></span>
             <span class="sit_opt_prc"></span>
             <div>
              <label for="ct_qty_<?php echo $i; ?>" class="sound_only"></label>
              <input type="text" name="ct_qty[<?php echo $it_id; ?>][]" value="<?php echo $it['it_buy_min_qty']; ?>" id="ct_qty_<?php echo $i; ?>" class="span1" placeholder="1">
               <button type="button" class="sit_qty_plus btn_frmline">증가</button>
               <button type="button" class="sit_qty_minus btn_frmline">감소</button>
             </div>