Failure resonponse
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Header>
      <h:ResponseContext xmlns:h="http://purolator.com/pws/datatypes/v2" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
         <h:ResponseReference>ff787f7e-351e-49fb-b029-6dc2d835dc5b</h:ResponseReference>
      </h:ResponseContext>
   </s:Header>
   <s:Body>
      <GetFullEstimateResponse xmlns="http://purolator.com/pws/datatypes/v2" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
         <ResponseInformation>
            <Errors>
               <Error>
                  <Code>3001149</Code>
                  <Description>Invalid sender postal code specified. Postal Code does not match any of the registered Postal Codes associated with the supplied Key.</Description>
                  <AdditionalInformation i:nil="true"/>
               </Error>
            </Errors>
            <InformationalMessages i:nil="true"/>
         </ResponseInformation>
         <ShipmentEstimates i:nil="true"/>
         <ReturnShipmentEstimates i:nil="true"/>
      </GetFullEstimateResponse>
   </s:Body>
</s:Envelope>
Success Response:-
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Header>
      <h:ResponseContext xmlns:h="http://purolator.com/pws/datatypes/v2" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
         <h:ResponseReference>ae3ec807-6442-4581-848c-bbd6af200a48</h:ResponseReference>
      </h:ResponseContext>
   </s:Header>
   <s:Body>
      <GetFullEstimateResponse xmlns="http://purolator.com/pws/datatypes/v2" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
         <ResponseInformation>
            <Errors/>
            <InformationalMessages i:nil="true"/>
         </ResponseInformation>
         <ShipmentEstimates>
            <ShipmentEstimate>
               <ServiceID>PurolatorExpress9AM</ServiceID>
               <ShipmentDate>2018-07-17</ShipmentDate>
               <ExpectedDeliveryDate>2018-07-18</ExpectedDeliveryDate>
               <EstimatedTransitDays>1</EstimatedTransitDays>
               <BasePrice>199.69</BasePrice>
               <Surcharges>
                  <Surcharge>
                     <Amount>30.4</Amount>
                     <Type>Fuel</Type>
                     <Description>Fuel</Description>
                  </Surcharge>
                  <Surcharge>
                     <Amount>2.95</Amount>
                     <Type>ResidentialDelivery</Type>
                     <Description>Residential Area</Description>
                  </Surcharge>
               </Surcharges>
               <Taxes>
                  <Tax>
                     <Amount>0</Amount>
                     <Type>PSTQST</Type>
                     <Description>PST/QST</Description>
                  </Tax>
                  <Tax>
                     <Amount>0</Amount>
                     <Type>HST</Type>
                     <Description>HST</Description>
                  </Tax>
                  <Tax>
                     <Amount>11.65</Amount>
                     <Type>GST</Type>
                     <Description>GST</Description>
                  </Tax>
               </Taxes>
               <OptionPrices i:nil="true"/>
               <TotalPrice>244.69</TotalPrice>
            </ShipmentEstimate>
            <ReturnShipmentEstimates i:nil="true"/>
      </GetFullEstimateResponse>
   </s:Body>
</s:Envelope>
How to parse this using dom. i'm pretty new to xml please help me