Lay the flex board over the PCB and align it. You can use tape or blu-tack to hold it in place. Apply some solder to tack the flex pad to the PCB pad.
Please be careful with TL pad as you don’t want to accidentally touch any of the components nearby, we recommend using this soldering angle. It’s normal that the flex PCB won’t be laying flat on the antenna side due to a component underneath.
Place the included pad under the antenna to lift it off the PCB. If you don’t, the wireless range will be greatly reduced.
You can power up your GB/GBA/DS transmitter cart and press the buttons, you will see the LEDs on the flex board light up.