how to get sump off

[TheG]

Hi i need to remove the sump of my engine, long story i dropped something down a oil well so if its not in the sump the engine will need to be rebuilt,

i have undone all the bolts on the sump and spent 20mins going around the sump with a mallot, i cannot get it off

question does the sump sit on dowels as the downpipes are sat underneath, do i need to remove the downpipes ?