The document provides instructions for extending a UDP server to handle additional commands for reading the state of GPIO pins connected to LEDs on a board. The UDP server extension should accept "read gpio<PORT> <PIN>" commands to check the status of LEDs connected to pins 13, 12, 14, and 15, and reply with the pin and state like "GPIOD.15=1". The ncat utility can be used as a UDP client to send commands to control the LEDs or get their status by communicating with ports 5678 and 1234 of the UDP server, respectively.