hey i was in the same situation as you. Needed to change the oil on 500R but had no idea what I was doing. Anyway I found this page here:
http://www.grandcorbeau.com/nest/EX500/wrenching/oil.html
which gives you a great step by step guide of how to do it (props to the guy who's site it is)
It's a little bit tricky the first time (I have no mechanical abilities whatsoever) and I managed to do it
As far as what oil you need - what I did was just goto a motorcycle deal and ask them to just give me the right oil and filter. If you can't make it to a kaw dealer you could probably just phone one and ask, usually they are really helpful with stuff like that.
Getting the oil drained was the hardest part, it's tricky to get the plug out without getting oil all over the place. My advice to you is loosen the plug with a wrench to the point where you can use your hand to twist it out. Then with whatever you are catching the oil in right beside you pull the plug out really fast and with the other hand slide the pan under the bike. This was my method (I'm guessing not the best) and I only ended up dropping maybe a couple table spoons of oil on the ground.
Also getting the filter off was actually way easier then they made it sound on that page. My advice is just use your hands to get it off, no point in buying one of those silly wrenches. I found it was actually pretty easy to get off with just my hands.
Hope that's helpful, good luck with the oil change. It's actually suprisingly not that hard.
