I'd use brake cleaner spray rather than plain petrol. Mainly because of the large number of seals in various places down there.

Don't forget to clean the oil off the brake discs before fitting

I meant I'd use petrol to clean the oil off the discs, not to clean the calipers and sliders!

Thanks all - these are new discs so was planning on the petrol clean away from the car and definitely well away from any rubber bits and seals!

So I'll make sure I have impact driver & Drill to hand and various sizes of hammer (claw . . club . . sledge!)!

Just collected a set of discs from Camberley Auto Factors (delco?) and bugger me they're a bit heavy. Not sure my little Honda C90 cub will cope with me plus those on the way home!! The brakes on that are a bit spongy at the best of times let alone with that extra weight!

Just how important is that little screw if I make a hash of getting it out? I'm assuming the wheel bolts do most of the holding? Is it really there just to stop the disc falling off when removing the wheel?

I meant I'd use petrol to clean the oil off the discs, not to clean the calipers and sliders!

Ahhh right, yes.

As for getting it off. My MK I required an impact driver to get the screw out and repeated blows with a BFO (but obviously not big enough) hammer didn't get them moving.

Finally gave up and dropped it into a garage near work for cash and they has to use some sort of press after heating and cooling failed.

The screw is handy, because it stops the disc rotating on the hub when the wheels are off. That said, the original reason for them was just (back when most cars used nut and stud wheel location) to hold the discs on when the car was on the production line.