In the below XML, I need to find timestamp in `<LastUpdated>` tag with single digit 0 millisecond and update them to 000. Trying Sed for this but keep getting error.

```
<Order>
<OrderNbr>136642</OrderNbr>
<CustomerName>MIKE</CustomerName>
<CustomerType>NEW</CustomerType>
<DateOfBirth>09/03/1986</DateOfBirth>
<LastUpdated>2012-03-28 00:01:02.0</LastUpdated>
</Order>
<Order>
<OrderNbr>145645</OrderNbr>
<CustomerName>STEVE</CustomerName>
<CustomerType>NEW</CustomerType>
<DateOfBirth>05/08/1986</DateOfBirth>
<LastUpdated>2014-03-28 10:09:04.456</LastUpdated>
</Order>
<OrderNbr>128965</OrderNbr>
<CustomerName>MARK</CustomerName>
<CustomerType>NEW</CustomerType>
<DateOfBirth>04/09/1989</DateOfBirth>
<LastUpdated>2016-04-28 12:19:06.0</LastUpdated>
</Order>

```

**Expected Output:**

```
<Order>
<OrderNbr>136642</OrderNbr>
<CustomerName>MIKE</CustomerName>
<CustomerType>NEW</CustomerType>
<DateOfBirth>09/03/1986</DateOfBirth>
<LastUpdated>2012-03-28 00:01:02.000</LastUpdated>
</Order>
<Order>
<OrderNbr>145645</OrderNbr>
<CustomerName>STEVE</CustomerName>
<CustomerType>NEW</CustomerType>
<DateOfBirth>05/08/1986</DateOfBirth>
<LastUpdated>2014-03-28 10:09:04.456</LastUpdated>
</Order>
<OrderNbr>128965</OrderNbr>
<CustomerName>MARK</CustomerName>
<CustomerType>NEW</CustomerType>
<DateOfBirth>04/09/1989</DateOfBirth>
<LastUpdated>2016-04-28 12:19:06.000</LastUpdated>
</Order>

```