Replacing Antenna Base on 04 Avalanche

On top of me needing to replace the sensor on my dashboard, I also need to replace my antenna base.

Luckly it's a two piece system that doesn't need for me to fish it all the way back to head unit.

NOW, has anyone had to replace this or does anyone know of anyone that works at a shop that has done it?

Good lookin out.

No GM mechanics or anyone that has done this....?