It was easy as hell for me.
This is what I did.
1. Got the pedals, sat down infront of tv. Got a spoon (yes a metal spoon) and jammed/squished it around the edges of the pedals (stuck the spoon end in and went around the edges to loosen them). Did that for a while till they felt soft.
2. Turned on my tap on hot till the water was very hot, if your water doesnt get too hot boil some (I dont know If I would bring to complete boil). Drop the pedals in for a while, now they should be nice and soft.
3. Go around with the spoon again while there still fairly warm, take it easy you dont want to tear them.
4. Get hot water again (doesnt have to be super hot this time) in a little pail, add a good amount of sunlight soap and put the pedals in there and stir it around
5. Go to your car, get the pedals, take one out at a time and put the bottom of the pedal on first, try to pull up/streach it up as high as possible. SIT IN YOUR SEAT, then jam your foot on the pedals pushing in a upward motion (and kinda wiggle left and right just mash them good lol) forcing them on. This is the trick! They should go on pretty good, you might have to get a nice rounded (not sharp so u dont tear) screwdriver or somthing along those lines and go around to make sure its on.
6. Enjoy your new pedals.
For the gas pedal I didnt care about my old one so I just forced it off snapping the old one, easier then trying to be superman and looking thru/behind the plastic for the pin.
Thats what I did...hope this helps and I didnt just waste 10 minutes writing it up.