If you're changing the whole peddle then the electrical connector on the back is the easy bit just take your time. The actual body of the accelerator however is held on with two hidden clips underneath the base of the pedal which locks onto two metal lugs attached to the footwell floor. You'll need two thin blade long handle screw drivers and three hands. The pedal has a flat base, push the pile of the carpet down with your hands and you'll see two small spaces which you put the screwdrivers into. You have to twist one to the side and push the other straight in but i can't remember which one is which. This basically releases the sprung catches and the pedal should pop off. If you break them a new ones £125 from the dealers.
Ps, there's a third bolt on the side of the pedal to the side of the connector under a little plastic cover.
