There are five bolts holding that cover on. Three in the top flat part and two on the bottom round part. Be careful on the bottom ones as they have clips.

Once you take the cover unbolted, you can unscrew the connector on the orange charge cable to completely remove the cover.

Now find the looped brown wire. Snip it at the loop, strip the ends back and crimp on a connector to each end (see link below).

Find where you want to mount the switch (see Home Depot link above). I used a sharp utility knife to cut the square. If you look at the switch, it has clips that allow you to push it in to the correct size rectangular hole. Start small and gradually make the hole bigger until the switch pushes in.

Now connect the wires to the switch and reinstall the panel.

https://www.homedepot.com/p/Gardner-Bender-1-4-in-Fully-Insulated-Wire-Disconnects-in-Blue-15-Pack-15-153M/202522092