Turn on the receiver (pictured below) and set it to the required channel. Make sure this channel is different to other nearby receivers.
Turn on the transmitter/microphone with the bottom cap off. Hold the microphone with the EZ sync port (pictured below) facing the receiver around 50cm away.
Press the EZ sync button on the receiver to transfer the channel info to the transmitter/microphone.
The receiver should say "SYNC" until the transmitter has synced, otherwise will say "ERROR" if unsuccessful.
If successful, the transmitter should/microphone should show a matching channel number to the receiver on the display (pictured below). Otherwise, try again. If you're not having any luck, try replacing the batteries or moving the receiver and transmitter to a shaded area, away from direct sunlight.