The official 'Ford' way to remove these is to purchase a drilling guide which fits over the centre post and allows you to drill straight down the middle with a 6mm drill and drill the bolt out. ( Special Service Tool Ford Part Number - 418537). When we supply these ECUs or rebuild them , we supply on request a replacement bolt (Hex Head!) for the ECU to be refitted. We got fed up with people fitting the rebuilt ECU and having bad connections and reliability problems when they had fitted the ECU back without a bolt.