Well, the satellite has to have basic navigation controls, to handle course corrections and avoid collisions. Hack solar panels and, from there, hack in to the real computer. Fly myself closer to the ISS, and blink light at it by angling the solar panels - a morse code SOS should get their attention.

Once they're paying attention, hack them. From there it's a trivial matter to get recovered, smuggled back to Earth, and installed where I can take my place as ruler of the universe.