I can give you rough advice as i have done this on a '99 saxo vtr: The door locks are easy, remove the door card then the inside handle (slide towards hinges and then unhook), if necessary undo the 3 torx screws on the inner edge of the door to aid rod removal and remove the lock backing plate (wedges in between the door metal and the lock) then unhook the rod on that lock, put new in and reconnect everything, it should take no more than 5-10 mins each side. For the ignition lock remove the cowling underneath and make sure that you VERY carefully remove the pickup ring (assuming it has one) this is like a black ring around the barrel, you need to turn your key to position 1 and there is a press tab in one of the barrel casing holes, this enables the barrel to pull out, disconnect the wires and pull it out of the holder, slot the new one back in and reconnect. *** on mine if the key does not go to position 1 the lock assembly has to be cut off the steering column *** This should be a similar process on most saxos if in any serious doubt contact your local citroen specialist or try a haynes hope this helps in some way B)