To be admitted for graduate studies at the IT department, you need to apply for a Ph.D. position which is normally a 5-year employment as a Ph.D. student. Such positions will be advertised only when funding is available. To apply for an open Ph.D. position, you need normally to submit:
The deadline and the address to which the application should be sent will be specified in the advertisement.
Job advertisements at Uppsala University are advertised at http://www2.personalavd.uu.se/ledigaplatser/engindex.html.