Considering the overlapping of September exam session and plan of study definition period, student could not be able to define a part-time plan of study (because of still not registered or attended exams). 
Those enrolling full.time, because lacking the requirements (less than 36 credits left, final exam excluded), could ask for the conversion from full-time to part-time enrolment, in the following cases: 

•  students that reached the necessary requirements to enrol part-time within the last session of a.y. 2012/13 (September 2013);
  
• graduating students that chose the full-time enrolment anticipating Master degree credits, which were erased from plan of study because they didn’t reach the necessary amount of credits within September exam session. 
  

For the conversion, go at the Registrar’s Office (groud floor, Cittadella Politecnica) desks before 29th of November 2013. 
 
Remember that enrolling part-time the student has to pay immediately fees (see Fees regulation).