accelerator spring

Hi I have searched the forums and the net to no avail. My accelerator return spring has lost a bit off the end so doesn't work, I've got a new one and went to fit it today, but I can't seem to see clearly how to just remove the pin that runs through the middle of the pedal so I can refit a new one, I tried knocking it out but didn't want to use too much force in case i was doing it wrong, do I have to undo the whole pedal to do this or should that pin knock out (from left to right?)

ta

mandy

ps I did soak it in wd the other day to make it easier