Connecting Stock Radio

[HarukoE30]

Car: 1986 325
Headunit: Stock BMW Unit w/ picture below
Premium System: No
Fader Knob: Yes, but wire end is gone :(

I need to know which wires go to watch, by color code. It needs to be so simple that a 2-year old could do it by just color matching if possible. Thanks

[HarukoE30]

Any help? Looked at stickies, still can't figure it out.

[German Audio Specialties]

It would be MUCH better if you found a "slider" radio