If manual radio tuning is set it can be tuned in normal view and in the frequency list.
Radio tuning in normal view
Short press - FM mode on 
/ 
on the centre console (or steering wheel keypad).
/ on the centre console (or steering wheel keypad).Radio switches to previous/next stored station.
Long press - FM mode on / on the centre console (or steering wheel keypad).
/ on the centre console (or steering wheel keypad).Radio switches to previous/next available station.
Radio tuning in the frequency list
Turn on FM mode in TUNE, FM tuning is shown.
Turn TUNE to a frequency and select using OK/MENU.
Switch between manual and automatic radio tuning in the frequency list by pressing INFO in the centre console.