BMW E36 DIY on replacing the oil filter housing gasket, vanos oil line, and the oil pressure sensor. 
You don't necessarily need to replace all of these parts, however they are easily replaced if you are already replacing the oil filter housing gasket.
Replacement of the oil houing gasket is pretty quick, should take under 2 hours. 
Parts needed to remove:
Alternator (2 bolts, 2 wires on the back)
Serpentine Belt (From the tensioner)
Airbox
Disconnect Vanos oil line
Idler Pulley (if applicable)

Tips:
Power steering pump will come off with the filter housing.
Disconnect the battery prior to removing the alternator.
Keep the bolts in order, they are different sizes.
Rub some oil on the new gasket, helps make a good seal.