Becker BE 612 Replacement
 

Hello,
I am a new owner of a 1984 500SEL and am replacing the (failing) Becker BE 612 with a RetroSound Grand Prix M4HD. I have attached pictures of the Becker before I removed the wiring and a stock photo of the back of the RetroSound. I have a Metra wiring harness adapter so no wires need to be cut. I do, however, have two questions.
1. What do I do with the two brown wires attached to the bolt in the middle of the Becker (circled in the picture)?
2. How do I go from the rolled clip on spade terminal (circled in the picture) to the female Motorola plug in the RetroSound wiring harness for the power antenna?
Thank you so much.