PHP MySQL ลบภาพปัจจุบัน และใส่รูปภาพใหม่เข้าไปอย่างไรครับ

  <?php
        if(isset($_GET['pro_id']))
        {
          $pro_id=$_GET['pro_id'];
          $sql=" select * from productview";
          $sql.=" where pro_id=$pro_id";
          $result=$cls_con->select_base($sql);
          while ($row=mysqli_fetch_array($result)) 
          {
            $pro_id=$row['pro_id'];
         	$pro_pic1=$row['pro_pic1'];
           	$pro_pic2=$row['pro_pic2'];
           	$pro_pic3=$row['pro_pic3'];
			echo "<td><img src=\"../upload/".$row["pro_pic1"]."\" width='400'/></td>";
			echo "<td><img src=\"../upload/".$row["pro_pic2"]."\" width='400'/></td>";
			echo "<td><img src=\"../upload/".$row["pro_pic3"]."\" width='400'/></td>";
          }

        }

        ?>