From Lasors Section H1.4
http://www.caa.co.uk/docs/175/srg_lt...ection%20H.pdf
Removal of No Applied Instrument Restriction
a. Hold either a valid single pilot, Instrument Rating (IR(A)) or Instrument Meteorological Conditions (IMC) Rating.
b. Hold a valid FI(A) with Supervisory Restriction removed.
c. Have flown at least 200 hours flight time in accordance with Instrument Flight Rules (IFR), of which up to 50 hours may be instrument ground time in an approved flight simulator or FNPT II. Where pilots have recorded flight by sole reference to instruments and not under IFR then 1 hour of flight by sole reference to instruments may be counted as 4 hours flight by IFR. Where pilots wish solely to instruct for the IMC Rating a reduced experience level of 10 hours flight time by sole reference to instruments is applicable and;d. Complete an approved course comprising at least 5 hours dual flight training on instruments in an aeroplane, flight simulator or FNPT 2 and 10 hours of theoretical training. All training to be conducted by FIC Instructor qualified to conduct instrument training at an approved FIC FTO.
e. Pass the relevant elements of a FI Skill Test in a single pilot aeroplane with a suitably qualified FIE(A).
So unable to do it in a SIM - clearly states aeroplane!