the bonnet release lever just pulls off (from experience)
not sure about the plastics - have a look in Haynes if you've got one, as the interior trim is described in there. fairly sure i had the panel behind the bonnet release lever off and that it just pulled off (hook-type clip at the top?) - if unsure, feel for resistance to identify where the clips are, then see if you can bend it back to see what type of fixing it has, rather than just yanking it off