The bolt heads on the prop flanges are torx and the nuts metric, easier to spanner off the nuts as they are bigger than the bolt heads if you don't have torx spanners/sockets. You will also have to turn the rear wheels so you can get to the top diff flange bolts (just a point to remember if you have the car on DIY ramps). Dropped my props and VCU off a few weeks ago for the same reasons that you have, my intention is to fit a recon VCU when I get the chance but the increase in performance and improved MPG suggests that I wait until the bad weather. You should inform your insurer as this will be classed as a modification and could result in higher premiums or a rejection of any claim (if you don't).