Never used bimmercode but i've heard its just plug and play. So I guess this is without doubt the easiest way to code.
The other method is using a cable and e-sys software. This really isn't for the faint hearted and you need to remember that you can make serious mistakes with this. There are plenty of guides out there to get you started.
http://www.bimmerfest.com/forums/sho...d.php?t=983245
http://www.bimmerfest.com/forums/sho...3#post10193333
http://www.bimmerfest.com/forums/sho...3#post10193333
It takes a while to download all of the software and ensure you have the correct PSDZData for your car. And then you need to check and double check then even triple check before writing anything to your car. I've learnt this the hard way. And be prepared that without ensuring you know what you are doing, you can quite easily brick modules in your car. There is nothing quite like that feeling when you make a mayor mistake and you get a picture of a car on a ramp when you start the engine.
Anyway lots of scary stories and i've never coded a G30 but done all of my other BMW's. Once the setup is done, you are good to code. I'll probably get all of the files I need for my car I'm just not totally sure if there is really anything I want to code this time around. Might try coding the Enhanced blue tooth to get the office integration.