as above: straight swap, no modding, the old ones can be pried off pretty easily (once warmed up) and the new ones should be straight forward (with a bit of sweating and swearing) to slot on:but as mentioned already; lots of hairspray and pre-soak in warm water and have a hairdryer ready to run in the footwell too, to warm them up a bit more... only things I'd add is you need a nice collection of old (smooth) flat head screw-drivers and make sure you're comfortable on your knees (cushion, etc)... I used a small set of bike tyre repair "paddles" (that you use for removing tyres)... which limits the chance of nicking the rubber because you will need to be very first with them.
I've posted the times before, but it was something like 1mins for the footrest, 15mins for the clutch, 10mins for the brake and then about an hour for the accellerator, but then I didn't start the pre-warming and lubricants, etc PROPERLY until about 30-40mins into doing the accelerator.