This is a fiddly step so take your time. You must now push the engine bay end of the gorilla knob cable through the rubber grommet from the engine bay to the inside of the car.

Firstly, pull the grommet itself out of the hole in the engine bay closer to you to give yourself more room to work.

Now, pull the throttle cable through the grommet and set it aside. Take note of which hole it went through for reassembly later.

Now you can work the gorilla knob cable through the hole towards the engine bay. It takes some persuasion but it does go through.