[fdihd]

Hello, I want to upgrade my E84 from the base audio system to the Harman Kardon one. I've bought the speakers, amp and wiring but I need some help regarding the installation. I wasn't thinking I would do it myself but I was not able to find any local shops/services that are able to do it.
The Harman Kardon system I've bought its from the same e84 model. The only difference would be that mine does not have navigation.
My questions would be:
1.What device/software would I need to connect via ODB to code the car to HK option?
2. I've checked the amp harness and saw there are 2 cable for positive/negative. The positive cable is very long and I would say it can reach the radio player, and the negative one is short. Should the amp be powered from the radio cd player? Where would the negative cable be connected?

Thank you.