If the roundel is fitted as per the bonnet, I did the following:
Fitted masking tape all around the roundel.
Using an old credit card, I eased this under the roundel and with a small broad bladed screwdriver gently prised the roundel up. You'll need to move the card around the roundel prising up as you go.
Heating the roundel with a hairdryer prior to doing all the above will help, as there is a spongy glued disc under the roundel that you can't see.
Then this link will take you to the new roundel (scroll down)
http://www.c3bmw.co.uk/StockItem.asp...&Item=unassign
Or if you want to give us all a laugh, fit these
http://www.c3bmw.co.uk/StockItem.asp...&Item=unassign