Briefly, go south on World Drive (leaving the MK Car Care Center) to I-4 north toward Orlando. Get off I-4 at Universal Blvd. exit.
More explicitly, from the Car Care Center stay in the right hand lane on World Drive in order to take the first exit. That is Epcot Center Drive (that becomes SR 536) which takes you to I-4 north at Exit 65 on I-4. Stay on I-4 to exit 75a which takes you to Universal Blvd. At the stop light turn left. Stay in the right hand lane to go to Universal parking.
You probably already know where the Hard Rock Cafe is at Citywalk?