Update to the above after i looked at some pics i took whilst doing this job. Rather than using a Euro pallet i used the the U shaped base frame of an engine stand which has castors on it and shimmed this to the subframe in 3 places. This made it easy to pull the assembly from under the raised car.
Whilst the engine and subframe are out it is a good time to replace the brake pipes and touch up any paintwork problems as these jobs are very hard with the engine in place.