Just undo the 7(?) bolts and take the covers off! If you dont have a socket set with elbows to get to the tricky ones it might be easier to take off the the air intake pipe & alternator. Also if the gasket is/gets broken or even looks pretty cruddy it would pay to replace them, they're only like < $15 from holden, save yourself the possibility of an oil leak... which i should have done when i took mine off just to see what it looked like inside
Heres my painted and 'modified' (as in busted a hole in it and glued a grille to it) super6 cover. Its the same colour as the car, though i like the writing you've done in the different colour Arth... might do mine black when i take the rocker covers off to paint them & replace the gaskets.