1994 540i maintenance help

[rdunnii]

I just recently purchased a 1994 540i and would like to do some basic routine maintenance. For starters, where is the oil filter located? Second, the previous owner recommended 20W50, is this a good viscosity for So Cal driving (30 mile per day commute)?

Finally, the engine is dirty and oily dirt needs to be removed, any suggestions besides those nasty degreasers? Oh, how do you remove that plastic cover that sits on top of the motor?

Thanks
Bob D