Re: sump leaking
This isn't such an easy job as folks think!
Firstly, one of the drive shafts runs through the sump casting at the rear of the engine. To remove the sump, the drive shaft has to be removed first!
The drive shaft, once released, has to be taken out through the wheel arch, this can only be done after certain suspension/steering components have been dis-connected/displaced.
Secondly, there are two 'hidden' sump screws up by the clutch. You will need a fairly long, thin bladed Torx or allen tool (T driver) to insert up the gap between the bell housing and it's blanking plate.
Thirdly, the sump will only initially come down an inch or so as it gets stuck on the angled oil pump pick-up pipe. This pipe is held by two 6m bolts, remove one, slacken the other and rotate the pipe CAREFULLY so as not to damage the gasket. The sump can then be removed.
The sump is gasket-less. Alfa use some black gunge, I used Loctite 574 Muli-Gasket (£16.39) with good results.
In our case, it turned out that the sump wasn't causing the leak but the oil pump cover gasket. This cover is the one that also houses the front crankshaft seal. It's gasket is aluminium.