Warm the car up first a bit, also (not knowing yet what side the drain plug is) it sometimes helps to slightly jack the opposite side up (not high, just a couple of inches will be fine, that way it can stay on it's wheels and be safe. Make sure you are prepared for:-
Hot oil gushing out - it will scoot out then slow to a dribble so think about where the pan should be located
Dropping the sump plug (see above)
New sump plug washer if these have them
Oil dripping from the filter after you remove it
Basically just be prepared for oil dripping every where you don't want it to!!
And as Chris says, put the sump plug back in, after wiping the hole carefully, put it in by hand then tighten when you are 100% sure it isn't cross threaded
When you've done that and done the filter, it's always good practice to have blue roll/tissues/rags around the filler neck as oil has an awful tendency to go everywhere but where you want it to.......
Check the level, when happy start the car - DO NOT REV IT - let the oil circulate and keep an eye on the oil light. If all good leave it to run for a bit but keep checking underneath for leaks. Once it's run for a few mins, leave a few mins, then check the oil level again. Do not overfill. Final leak test then off you pop for a wee drive to get it nice and warm then bring home to check again for leaks.
Makes it sound way more complex than it is, you'll be fine!!!
