Hello.
Coding is actually a fun & simple task. Basically after some setup, you just flip some switches to activate the functionalities you desire through your computer. The key is to know which switch to flip since the system is crowded with only code names but no meaningful titles.
Anyways, here is the URL to a PDF I've used to code my Bimmer.
http://www.bmwesys.com/guides/Beginn...e%20Coding.pdf
This PDF provides both the stuff you gonna need to download and instructions you'll need on using them. So it's a good documentation to start.
As I've told above, the coding E-SYS lists are just coded numbers and letters so you gonna need a map. If you Google `BMW 1 Series F20 Cheat Sheet`, loads of results will be displayed. I'm not providing a specific one because various sources provide different modules with some minor differences. But it's easy to acquire one.
Also do note that the coding E-SYS will display have every option a 1-series could possibly have but in order for one to properly get activated, you'll need the specific accessories, hardware for them. So if something does not function even though you've coded it, keep this in mind.
There is actually more to coding but I just gave you a crash course. Hope it's been helpful. Also Googling will provide you a lot more. Lots of people code their Bimmers.
It's a genuine joy to code your Bimmer and get more out of her! If you have additional questions please don't be afraid to ask them.
Good luck and have fun!