well you have to start by taking out your headlight units... then heat up the mastic between the glass and rear unit.. so you can sepperate the 2 once you have done that its a case of siliconing them in place around your 2 lights inside and making a little hole in the back of the unit to put the cable though then using silicone seal the hole and cable so that you dont get condensation
inside the unit... the with black mastic you have to seal the glass back on..
craig