A Little Rear End Oil Change Help

I'm changing the gear oil in my 2000 Silverado's rear differential tonight. Can anyone give me some tips, it's the first time I've done it. Is there a drain plug, or do I have to remove the entire cover? If I have to remove the cover, do I have to replace any gaskets? How full do I fill the differential? Thanks for any help.....

Well, there is only a check plug on the side, just above the driveshaft. You can either remove the cover (you WILL need to replace the gasket) or use a syringe/hose to suck the fluid out. Fill the diff until the fluid level is at the bottom of the check plug (when the fluid is barely dribbling out of the hole, plug it) The syringe will also help in filling the diff. The angles can get VERY weird.

Thanks a bunch Chris! I didn't think anyone was going to respond.