This video shows you how to install a Composite Video Modification board into an Atari 2600 "Sixer" Console. This mod is non destructive, there is no soldering, or drilling holes, just plug it in, and you are ready to go.
Atari 2600 "Sixer" Mod board
https://www.etsy.com/ca/listing/1849176851/atari-2600-sixer-composite-mod-board-non
Atari 2600 Mod Board
https://www.etsy.com/ca/listing/1786984543/atari-2600-ntsc-composite-mod-board-plug
Atari Joystick Replacement Board
https://www.etsy.com/ca/listing/1762469682/atari-2600-joystick-replacement-board