Hijack is just a kernel, correct. It does require 2.0 of the player software though. So the proper steps would be:

1. Install the 2.0 Beta 7 upgrade file
2. Install the Hijack kernel
3. Check back on the hijack page in a few days, upgrade hijack, enjoy 1-5 new features
4. Repeat step 3.

Any time you apply a .upgrade file, you will then need to reapply the Hijack kernel.