vraddict,
Hi there,
Yep you're right you do need to pull the granade pin (cotter pin) and loosen the axle nut before proceeding.
After pulling the pin, oyu can lift up which ever side of the car you're working on and pull the tire, axle nut and the 4 bolts that connect the rotor to the hub.
At this point you should have the axle nut and 'wavy' washer and cone washer loose. If they're not loose yet, don't worry. Place a piece of 2x4 in between the end of the axle and a large hammer that you're going to use to 'impact' the axle with to 'shock' the cone washer off of the axle with.
Now that you (should) have the pieces set off to the side, it should be very easy to pull the hub off the axle, leaving the rotor behind in its happy little home.
At this point, you should be able to see how the caliper is going to un-bolt from the knuckle thus enabling you to throw the old POS rotor in the appropriate receptacle container. (Please let the other people around you know when you're going to throw something in a large empty bin by saying "NOISE" loudly so they don't mess their panties and such. Just a helpful hint from someone with laundry experience).
Regarding the puller, forget it. A brass hammer will work great when the hub is being difficult. Just keep smacking the back-side of the hub on a triangular pattern so it comes off evenly.
I can't tell you how many times I've done this job and never had a problem.
Don't sweat it!!
If you have any questions, zap me at avsfanlarry@yahoo.com
Don't forget to have fun with the project!!! Geez it makes it better!!
Later,
Larry