I see this thread is a bit stale, but don't grind those rivets off unless you want to seperate the drum from the hub.
Pull the dust cover, remove the cotter pin and castellated nut and slide the assembly off the spindle like the Andice said. It is far less work than it sounds.
It's a PITA to post images here, so instead I'll point you to my craigslist ad that has images of 69 front drum/spindles so you can see an example of a disassembled drum:
http://sacramento.craigslist.org/pts/4774782732.html