All you need to do is visit an Italian post office and withdraw the required form known as "kit permesso di soggiorno" ("soggiorno" sounds like "sojjorno"). Then, bring it to campus and we'll fill it in together!
After that, put all the required documents (including blank forms) back in the envelope, visit an Italian post office once again and complete the submission process (including payment of the required fees) with the post office clerks. After that, your application will be submitted to the L'Aquila police station ("questura" in Italian, which sounds like "kuestura") via the post office itself. Note that you may withdraw and drop your application form at any Italian post office, not necessarily the ones in L'Aquila, but the envelope must be addressed to the L'Aquila Questura, as it's the one in charge of the place where you're going to live and study.

At the end of the submission process, the clerk at the post office will hand you out three receipts, which will be considered as your temporary residence permit (always carry a copy with you whenever you're around and drop one to our Registrar's Office to confirm your enrolment).
On such receipts you'll also find the date and time of the appointment fixed for you at the L'Aquila police station (Questura) to complete the rest of the required procedures, which includes an interview for fingerprints (carry with you passport & ID-size photos). Eventually, you'll be summoned for another appointment to collect your final (plastic) permit card - the one you can see on this page.
The whole process will be complete in approximately 2 months (but it might even take longer) and will cost you around 120 euros.