The filter is accessed from the top of the motor, in a plastic housing. You need a web filter wrench to remove it. The replacment filters are all about the same. I get mine from FCPGroton on line, or my FLAPS (Friendly Local Auto Parts Store). About $9 for the filter, which includes the O-Rings (be sure to change these). It is a fairly easy oil change. I use Mobil 1 (10W30)... and 1 QT Lucas Oil Treatment. Total cost for a Home Change is about $32.00 most FLAPS will take your used oil.