as said above pull off old push on new, brake pedal may need to be stood on like mine cos its got a rubber plug to go through the pedel,
but v easy
 
spray the backs of the new tt ones with hair spray, it lubes them temporarily and makes them slip on well easy

then it will dry up unlike wd40 or washing up liquid and they won't pop off whilst your driving :D
 
For the brake pedal, I used a pair of long nosed pliers and pulled the middle lug through to secure it properly, took me all of 10 mins to fit then 2nd time. Much better than drilling your pedals for the likes of the Sparco ones.