hi just wondered if anyone can shed a light on how to remove this bolt so I can change the top mount thanks

You need one of these sockets http://www.ebay.co.uk/itm/5pc-Strut-Nut-Tool-Set-Fits-Audi-VW-Mercedes-Suspension-Repair-Refit-Tools-/371339806389?pt=LH_DefaultDomain_3&hash=item567593c6b5

You need a castle nut tool (although I have used a good set of vise grips before). They're not expensive, and something to clamp the shock insert in place.

You also need a set of spring compressors in place, or you will get smacked by a top mount doing 100mph .

If you can compress the spring with spring compressors it should be fairly easy to remove perhaps with some mole grips if you don't have the right tool. Just be very careful as compressed springs contain lots of stored energy and will hurt!