Both plugs are in the passenger end of the gearbox, so may have to take the inner wheel arch out
jack car up (but try and keep car level on axle stands), using 8mm square male socket undo the drain plug - drain fluid. Then do the bolt back up.
People tend to undo the breather ontop of the gearbox and pour 2 litres in there. Or can undo the top filling plug with the 8mnm square male socket and put 2 litres in there, fill until the oil just trickles out the filling hole on the side.