You would want to print the Work Orders lines instead of from the routing on the Manufacturing Order - the list of operations in the routing is copied to the Manufacturing Order as a list of work orders and the user could modify these items to cater to the nature of the said Manufacturing Order. 

1. Create a custom report: https://www.odoo.yenthevg.com/creating-custom-reports-odoo-8/

2. Add these codes to where you would want to print your work orders:
   <table class="table table-condensed">
       <thead style="display: table-header-group">
           <tr>
               <th>Sequence</th>
               <th>Work Order</th>
               <th>Description</th>
               <th>Work Center</th>
           </tr>
       </thead>
       <tbody>
           <tr t-foreach="o.workcenter_lines" t-as="line">
               <td><span t-field="line.sequence"/></td>
               <td><span t-raw="o._format_work_order_name(line)"/></td>
               <td><span t-raw="o._get_work_order_notes(line)"/></td>
               <td><span t-field="line.workcenter_id.name"/></td>
            </tr>
       </tbody>
   </table>

We are currently evaluating Odoo. This seems like a vary basic function, Did you find a way to print the routing?