If you don't have a student number yet go to www.up.ac.za/apply
You should end up with this screen:
On the right hand side enter your T-number in the Application ID field and your password (you created it during the empowerment week last year).
If you have a student number go to www1.up.ac.za
You'll end up here:
If you have never been here before, create a portal ID by clicking on new user and follow the instructions using your student number as username.