Atari 5200:Ultimate Atari Video Mod (UAV) Board
The Brewing Academy's Ultimate Atari Video (UAV) board was originally developed by Bryan Edewaard as a universal mod board to allow composite and s-video output on various Atari systems. In the case of the Atari 5200, this board can be installed along the CD4050 chip to retain RF output or it can be used in place of the CD4050 chip for a simpler install.
The latest version of the official manual can be downloaded from The Brewing Academy's site or an archived copy can be found here - though it just directs you to use these instructions by Ivory Tower Collections.
Ivory Tower Collections also has great UAV installation videos for the 2-port Atari 5200 and the 4-port 5200.
Jumper Configuration
Configure the jumpers as shown in the picture below for the 5200. If your kit has pins and jumpers, you can insert them as shown. Otherwise, put a large blob of solder on each required pin, then drag them into each other to make the necessary bridges.