Depending on which database you located the dissertation in, your method of retrieval will differ.
If you used OregonPDF...
...your dissertation will already be available for download, OR you can request your dissertation be digitized by OregonPDF and it should be available within a few days.
If you used Dissertations and Theses...
...your dissertation may be available via full text, but in many cases you will have to procure your own copy of the dissertation - The Dissertations and Theses database may only provide you with the record of the dissertation, a summary, and a table of contents.
Fortunately, you can often retrieve a dissertation by searching the internet or requesting it via Ithe library's nterlibrary Loan service. Here are places to try and retrieve your dissertation.
1) Try using Google Scholar. (http://scholar.google.com) Enter the title of your dissertation in the search bar and see if you can locate a full-text PDF version.
2) Try using Google to see if the institution the dissertation was created for has an online or digital repository. Many larger universities and some smaller ones have digital repositories where dissertations, theses, and other academic works created by students at that university are stored.
3) Ask your librarian - they may have some additional suggestions on where to search or can verify that the dissertation is not freely available on the internet.
4) Request the dissertation via Bailey Library's Interlibrary Loan. It is recommended you use this as a method of last resort - however it is definitely an option if you have a dissertation or thesis that you believe will be invaluable to your research.
5) Visit the library website of the institution that possesses the dissertation. They may have a dissertation lending service independent of SRU's Interlibrary Loan, though there may be a fee or personal cost to access.
6) Contact the author of the dissertation and request a digital copy. Though a measure of last resort, many authors are happy to share the fruits of their labor with interested parties.