The pedal's are all 'hung' from a bar that goes across the footwell.
On each end of the bar there should be a clip holding it in place. So that the bar doesn't move.
In order to remove the pedals you need to unclip each end of the bar, to allow you to shim the bar along, so that you can remove the pedals. Check whether this bar has a clip on each end.
The clips are identified here as numbers 5 and 17, and the bar is number 16.