Especially the 2 litre diesel. IIRC, that needs to be partially craned out to get to the belt. Believe the petrol ones, including the ST, are a bit more straightforward.
No way you can do it properly in that time; the cam cover has to come off in order to time the cams, the starter motor has to come out to lock the crank, the cooling system has to be rebooted (ie run up to temperature and checked for full circulation)... 4 to 5 hours (without snags).