Originally Posted by CraigM

Colour (that's 'color' for you yanks ) in the top of the posts with a marker/felt pen, use an excessive amount of ink, then position the body over the posts while trying not to touch them. Once in position press down firmly to transfer some of the ink over to the body and use a reamer to cut the holes at the positions marked. Check how your body sits to determine what posts to use, i use the closer in ones but on some bodies they may be too close to the rear windscreen which you will need to remove for cooling