Fiting a tow bar

Hi, am new to the forum, and thanks to all who have given time to set this up and keep it running, Great job !
I have an A4 Avant 2.0 TDI (05) and have enquired from the dealers re fitting a Westfalier detatchabe tow bar, they want £1100- that cant be right ?, anyway, bought the kit on line from PFJones at £213 and thought I would have a look at fitting it myself.
Its quite hard to remove the interior trims, they feel like they might break if I force them, I feel I am fishing in the dark a bit, and may be trying to remove more tha I need to , Has anyone out there done a bumper remval on an Avant, and fitted a tow bar etc ? - have looked at the pre posts re VW, but would like A4 05 info if anyone has some,
many thanks Rob.