Upgrading MFD2 to RNS-510


FIA World Rally Car Champion
Hi all,
I'm upgrading my MFD2 DVD version to an RNS-510. I just want to make sure I've got everything I need to get started... some help/advice would be appreciated!
1) I've been informed said to me that as I had factory-fit MFD2 that I do not require the twin-jack FAKRA adaptor:

My MFD2 has got two (2) discrete wires with (2) FAKRA connectors... are these really "plug and play" or do I have to find this adaptor? I have a feeling I have to source an adaptor.

2) I am aware I need to change the AUX/CD ground connections as per this image:

3) I'm concerned about the usability of my multifunction steering wheel. I have a very early model GTI with the following steering wheel buttons: Phone (pick up), Phone (disconnect), Mute, Change Source... Track next, Track previous, Volume up, Volume down. I hope that makes sense.
Anyway, in this post:
This is suggested:
99% of the time, when the MFSW buttons do not work, you have a CAN-Gateway issue. You need to have at least an "F" gateway for the buttons to work with the RNS-510 if you have the buttons with only (1) phone icon. If you have (2) phone icons you need an "E". If you need to replace, get an "N" as this will incude the capability fo rear view camera and the media player.

Does this mean I need to change some physical hardware in the car? If so, what part number is required and where is the device I am meant to change? Is it a straight swap?
earlier in that thread, this is suggested as well:

recode RNS510 multifunction steering whell On and later OFF, then it'll work.

How do I recode the RNS510? Do I need a VAG-COM? And which of the above is the definite answer?

Any advice would be greatly appreciated :)