A while back there was some talk on getting some guides on doing the things we normally seem to take for granted, like the knowhow of changing your oil. Theres some things some people may not know so I figured I would go over them all. If anyone has anything else to add, by all means let us know.
Alright here is the writeup on how to do this.
The first thing is to try and get as much oil as possible into the oil pan. An engine that has been running recently (within maybe 3 hours) still has a lot of oil all over the engine interior and you need to let as much of this residual oil drain to the oil pan as possible before draining. You can change it right after it has been ran but the engine will be hot and so will the oil, making it a little hard on your hands when oil gets on them. It also leaves old oil in the engine which isn't necessarily bad but why change the oil if your just going to leave some of the old oil in the engine. If you want to do this, let the oil drain for an hour (or even overnight to get every drop). Sometimes it is better for wintertime when oil barely drains so draining a hot engine would be faster and allowing it to drain overnight ensures it all gets out. Keep in mind the new oil should be in a warm spot to easily flow into the engine.
Next step is the oil filter. For some reason they always tend to tighten over time (or because you used a wrench to get it on last time) so you may need to use a wrench to get it off. It really doesn't matter if you damage it since you are going to throw it away anyways, but a strap wrench usually prevents any damage. If you do have to use something intense like channel locks, make sure to grab the bottom half of the filter because you might crush the filter and if it is on the top half, you may damage the filter head threads. Ideally, you should be able to get it off by hand (which is why you put it on by hand). I can always get mine off by hand but they are always tighter than when I put them on (or maybe I'm getting weaker). Depending on the year of truck, you should be able to wiggle it out without spilling a drop of the oil inside the filter, then you can dump the oil in the pan the engine oil is currently draining into.
What you just unscrewed the filter from should be cleaned with a rag. Dirt gets up in there sometimes and it isn't the best idea to smash the new filter's gasket upon debris. I attached a pic of what I am talking about. Make sure the gasket from the old filter is not up there as well, if you forget to check and put a new filter on on top of another gasket, the 2 gaskets will not seal and the oil pressure will blow out between them. I have never had an oil filter leave that gasket behind but you never know, you will know when you forgot to check though..
Now get your new filter and write the current date and mileage on it with a sharpie BEFORE you do anything else with the filter (I did the next steps first and it made it a pain). Next step is to take the gasket off the new filter and get clean engine oil all over it until the whole thing is wet with oil, then push it back into the groove you took it out of. Now you can fill the filter to about an inch before it overflows, this will give you room to play before the oil spills out when putting it back in the truck. NOTE: If you spilled oil all over the place getting the filter out, you probably will spill a bunch of oil on the way back in, so you will have to judge how much oil to put in based on the degrees of tilt you had to attain to get the old one out.
The previous tip about filling the oil filter is not recommended these days because debris can get into the filter/oil during the installation process and that oil is unfiltered and goes straight to the turbo bearings which is not good. However, I still believe it to be better than having the turbo starve for oil for the time it takes the filter to fill up. Just be aware of this and know that any oil that goes into the filter (the big hole in the center) is the same oil that goes out from the filter and into the turbo..the holes on the outer ring of the filter are the intake holes that send the oil through the filter media).
Spin the oil filter on hand tight. I think the filters say go to where the gaskets gets tight as if you had the filter in a free spin and the gaskets resistance stopped it, then tighten 3/4 turn. I get it as tight as I can by hand and call it good. If you don't have good grip then you may need to resort to a filter wrench. This means dry hands dry filter, an oily filter tightened by hand is not exactly the tightest. Over time the filter tightens, I think because the gasket swells or something. Putting it on only hand tight ensures it can be taken off without channel locks or something drastic (hopefully).
After the oil is drained, tighten the plug back up. My manual says 60 ft/lbs, and I wouldn't go a ft/lb more than that! You shouldn't have to take the plug out to drain the oil since it somehow drains out 4 little things on the sides so you should never have to start the plug into the threads, meaning you will never crossthread it. If you do take it all the way out, just make sure it threads in a couple full turns by hand so you know for sure it isn't crossthreaded. Fixing a screwed up oil plug can be expensive and laborous on these things. You can get lucky and thread it the next size up but it's still a lot of hassle for something so simple to not screw up.
Now your filter should be in and tight, oil pan plug should be in and tight, so fill it up with oil. Every truck seems to be different these days so look up how much it takes. 94' 12V's take 10 quarts while 95'-98' 12V's take 11. Put the oil fill cap back on, start the truck, let it run a minute or 2, then turn it off. Check for leaks around the oil filter just in case you didn't get it tight enough by hand. If at all possible, leave it off for 3+ hours on level ground, then go back and check the oil level on the dipstick. Many people start it then instantly check the oil and wonder why it is not at the perfect mark. The perfectly full mark is an engine that has been sitting for a long time on a level ground. An engine that has been running has oil all over the engine and it takes a long time for it all to accumulate back into the oil pan, giving you a false reading until then. The dipstick has 2 marks; a full mark, and an add mark, with "SAFE" in between. The add mark denotes 2 quarts low.
You have now changed your oil.