Unless you are mechanicaly minded i would not attempt this job brakes is not something you want to get wrong risk of DEATH and i Hope you have got lots of tools 1st remove battery remove glove box remove roll pin connecting servo to brake rod a new pin will be required undo 2 master cylinder bolts move aside master cylinder without damaging the pipes remove 4 servo bolts glove box side pull out servo fit new square seal to new servo refit all parts removed ensure the master cylinder rod engages with servo rod or you will have NO BRAKES
Peugeot master technician, October 2008