The brake and clutch you just remove the stock rubber pads and slip the new ones over. You will need to use some soapy water as lube as they are very tight fit.
Slide the bottom and sides in then use your foot on the pedal to push down hard and upwards to clip the top edge in.
The accelerator pedal you have to unclip the harness then unbolt the whole pedal assembly out of the car. Use a hammer and punch with a vice to get the pin out then the same to get the new pedal on.
It's all pretty fiddly but take your time and don't break the pedal with your hammer
