Want to change a couple of things. What coding software to use?

[David D]

I'd like to change a couple of things in programming and don't where to start. Most importantly, I'd REALLY like to activate the halogen inboard high beams along with the bi-xenons. My night vision isn't great and every little bit helps. I'd also like to be able to change things like if the door locks unlock when you put the car in park, etc.

What's the best software and interface to use?