Hi,
When you purchase a Muse Luxe (they should be back in stock soon, but that’s another topic), it already includes an external antenna that improves Wi-Fi performance, so there’s nothing more you need to do.
If you decide to modify your existing Muse Luxe, you can certainly do so. However, as I don’t know your soldering skills, please note that this will void your warranty if it’s still applicable. This modification likely requires some magnification tools (like a lens or binoculars) to move the tiny resistor to the red position. The middle pad is for the antenna signal, and the bottom pad is the ground.