The Clutch and brake you can just take the old rubber pedals off and put the new ones on. There are holes in the actual pedals so just put them over them and secure them with a couple nuts and bolts.
The accel. pedal is a little trickier as the rubber pedal actually fits onto a bar type pedal, not a pedal looking pedal lol (if that makes sense) In the end I just drilled through the rubber pedal and fitted the pedal extension on top.
Its a bit wierd because of the extra thickness of the accel. pedal but you get used to it.....
Take the rubber pedals off and have a look, youll be able to figure out everything when youve had a proper look.
Hope this helps
Tom