First you should buy yourself a Bentley Service Manual. The wiper arms are held on by retaining nuts that are under the hinged cover at the pivot point. The linkage is accessible from the engine compartment by removing the rubber firewall cover which is held on by six screws. Make sure you mark the relative positions of everything in the linkage you remove so it will be aligned properly on reassembly.
Don't be gormless; get some gorm!