I'm looking for a step-by-step guide to changing the oil of 2004 Nissan Xterra. I found one a very useful one for my Lexus but I can't find one for my Nissan. Does anyone know of one or would like to write one?
For your car? It's going to be tough to find exact instructions. There are plenty of resources on the internet for changing oil in general. It's not a big deal at all, there are only a couple things to keep in mind:
Basically, avoid killing yourself and/or your car. I think those two are the only ways to really screw up on an oil change.
Car specific info
If your car is a VG33 Xterra (the 3.3L, that year they switched to a 4.0L), I can tell you that the oil filter is a canister type (the more widespread type). It should be on the driver's side toward the front of the engine, facing straight down. The 4.0L is also a canister, but I can't remember quite where. In the VQ35 Pathfinder, it's right above the crossmember, angled forward and down (45 degrees). You have to remove the plastic cover under the car between the bumper and the crossmember. I imagine it'd be very similar to that. Plus, the VQs have a drip guide (finally!).
The drain plug is toward the rear of the vehicle's engine. The 3.3L Xterra's have a very short lower oil pan section, you can't miss it. The 4.0L... can't remember what side, but it's there and hard to miss.
*You can leave a car on ramps and start it. You can on jackstands too... but if in doubt, swap 8 and 9 around.
Here are some good "how-tos" I found:
I noticed that some guides tell you do warm the car up before draining. Not sure why they would recommend this. You want the oil cool (when it hits your hand, hot oil doesn't feel good), and you want it all drained to the pan (when the car's off, all the oil slowly returns to the pan). Maybe, if you're in northern climates, you don't want molasses coming out, but still...
I change it in the morning when the car is stone cold.
A few tips that those How-Tos don't mention: