Hmm... If you are unable to get the sump drain out, its going to be messy! First thoughts are to remove spark plugs and disconnect crank sensor. Crank the engine over to oil pressure to fill the apollo tank, and this will partially empty the sump. Then remove oil filter and apollo sandwich adapter, elevate the latter to prevent oil running back to the sump. Then move the sump, not forgetting the two horizontal sump/bellhousing fixings. There will be still be some oil, so beware.
On refitting the new sump the gasket can be reused and no sealant. Total capacity for apollo system with filter is 7.5 l, so a bit of guesswork of the refill.