[skidlids]

checked and 12mm X 1.25mm pitch is the same as some spark plugs, but you would have to do it from the underside i suspect

Seeley do a tool
http://www.tooled-up.com/Product.asp...er-10-And-12mm

http://www.premiertools.co.uk/item2645.htm

http://www.spark-plugs.co.uk/pages/p...ance_tools.htm

http://www.toolsnstuff.co.uk/product...e 0ee868bd585