You can't easily, its riveted to the dash. You just have to work round it and its a major pain in the arse if your using a decent size cable, I fought for about 30 mins to get my 4awg through but once you can get a good hand hold of it on the engine side its easy, its just getting it started.
It will get frustrating, but stick with it, as long as you've got a decent size hole in the grommet it'll go eventually.