should be located located on the driver side of the engine and back against firewall. (May be under some hoses.) Can undo the top of the filter cannister to which the filter element attaches with the proper filter wrench. I use a 3/8 drive socket rachet and a 10" exention on mine.

I also use a MitiVac evacuation/pump device which I recommend.

I'm not sure i would use synthetic oil in an M104 engine. I'd prefer regular 5-30 dino oil.

Can do job in 30 minutes after the first time thru it.