How difficult is it to remove the mirrors, i think all the way down to the base plate.

I am trying to work out whether it will be worth the aggro of taking my mirrors off to be replaced by some dtm style units.

Also, i have electric mirrors and I'd like to know if it will just be a case of plugging them in to the new ones, or will some semi-technical electrical work be required.

You will need to remove your door cards and the interior plastic mirror cover, disconect the wires and remove the three screws holding the baseplate on from the inside of the door. You will probably have to rewire the new mirrors to the old connectors.