Got some hubcentric wheel spacers from ebay. Everywhere says you just take your wheels off, put them on and bolt the wheels back on. Problem is on my drum and on the front disk/hub bit where the wheel goes their is a pin and nut which means the spacer wont sit flush. I presume the pin is to help locate the wheel. The nut I am unsure about. Looking at them it looks like they both probably unscrew with a 8 or 6 mill spanner. Is it ok to take these off or will something fall off on the other side?

They are only there to hold the disk in line with the studs

You can take them off should you want

Excelent. Thanks for replying. Felt a bit of an idiot asking but paranoid about the wheels falling off or something. I presume this is the same for the drums at the rear? Both the nut and the pin?

You can take them off, but this will mean that the spacer will cheerfully fall to the floor when you take the wheel off. Oh, the joy of that happening when you get a puncture at night on a motorway...........

For best results, fit a stud conversion. If you want to use bolts, and if the spire bolt and plain bolt will fit the new wheel, use longer spire bolts (Alfas use much longer ones, probably a few FIATs) and longer plain bolts.