The first thing you must do is to not kill Dorian. That includes you people that like to go on killing sprees! If you already have, then do not do this cheat.

OK the first thing you need to do is make Dorian really angry at you (as in get his deposition down to zero).

Once that has happened bribe him until you bribe him no more.

Once that has happened get a paralyze spell on him and click on his body and keep repeatedly clicking on the gold non stop until your heart's content.