Ah right, the "Transmitter" fooled me, missed that bit.
The round button on the left has the + &- for volume and also < & > for tuning.. Hold the > for a couple of seconds to change from scan tuning to manual tuning.
When you find a station you want to store, press and hold a button 1 - 6 till it beeps, then its stored.
Alternatively press and hold the top left hand button marked mss untill the display starts to scroll and it will find the 6 strongest stations and store them randomly on buttons 1 - 6.