It's a real pain and there is no easy way to do it. If I remember correctly, I had to hold some wiring out of the way with one hand while using an 8mm (?) wrench and pliers in the other to remove the bolt. It was very slow going, like 1/8th turn at a time, so relax and have a beer in the process.
That's just the start. After getting the bolt out, you now have to fish the line through the wiring harnesses and hoses. You need to actually bend the metal portion of the line to striaghten it slightly on the steering head end. Then, pull it slowly to the rear of the bike, with the occasional twisting motion to work it through the maze of wiring and hoses.
After you work it through, pop another beer 'cause now you have to work the new line back through the maze......
(This was easier for me than pulling the original line)