How do I order a single or specific parts from a set/series using NExpress?

You can request specific volumes of a set or series via NExpress.  Start by finding the series in NExpress. The system will recognize it a multi-part set and ask you which volumes you are requesting AFTER you have entered your Middlebury login information.  

So go ahead with the basic NExpress request from the set record and once you have entered your affiliation and login credentials you will be able to select the volume or volumes you want to order.