I know this seems to be a silly question, but I never changed the oil on any of my vehicles myself. I want to start to change the oil on my 1984 380SL myself. Are there any special tools I need to get?

I understand that there is a filter housing on the engine, and all I need to purchase is the element. What tool do I need to remove the housing? Where is the oil drain located?

I also plan on using Castrol Oil (20W50 in the summer and 10W40 for storing over winter) on my oil changes, good or bad? Also has anyone used additives to clean engine just prior to oil change to remove any gunk?

Your advice to a newbie would be appreciated.