Hey Barney!! Welcome to the forums... and the greater Mazda family too.
'looks like you've owned some pretty interesting American iron over the years. My first car was a '57 Chevy 210, 2-dr, and I loved it, but have been into british, swedish, german and japanese cars nearly ever since.
As far as the oil change is concerned, I'm sure there's a write up on here some where. If you do a search you'll probably find something about , maybe w/pictures?
Basically, drop the undecarriage pan, I think it's 6 or 8, 8mm bolts. The oil filter is right near the front. There is a tool, but I usually just grab it w/my hand and twist like a spin off. Of course this is a cartridge style filter, so you will get a little dirty. Roll up your sleeves, etc.
The pan plug is on the back side/passenger (RS of the car.) And that's it! If you've done engine work, and had older cars this is not that hard. You might also consider switiching over to the 2.0 style spin-on filter. You'll need parts to do it, but I know there's a write-up about that here too.
Service manuals are easier and much cheaper online and on disk. I don't have one either but I've seen them for around $3.00 + shipping.
