I also fit it into my astra,
here are some pics:
the parts you need
(the black panel with 3 holes isn't avalible anymore)
step 1:
remove the relais box
take this connector under the relais box
Put the brown/white cable into this hole in the connector
here is the cable going into the car
in the car you will find the blue conector that you just put into the car
connect the blue cable into the new 'TC' button
and connect the grey cable that come out of the blue cable to the light of the sigaretlightner
TEST
