For a Newcastle University thesis, use Library Search (our catalogue) to find the thesis you want to request. [Hint: if you choose 'advanced search', you can restrict your search to theses by selecting from the 'materials type' box.] Click on the Locations/Request tab for the thesis entry and then on the 'request' link. This will take you to an online form. Fill in the details required and click on 'submit request'.
To request a thesis from another UK library, use the the British Library's EthOS service.