There are two ways to mount the RSD tweeters. One way is using the flush mount, which is a claw-like W shaped piece. This is the way I mounted mine and my favorite way.
Then there is surface mounting, which I'm not sure how that one works, but that's the way the guy above did it in the picture //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif.
I'll explain for the flush mount. Basically you put the tweeter in the flush mount housing, then you cut a hole the size of the tweeter into the door panel. I've found personally a door-knob drill used to cut door knob holes is the PERFECT size for almost all tweeters of that size, and it works great. Then you put the flush mount cup in, and screw the claw shaped thing behind it. Claw thing goes on the inside of the door panel so it kinda holds it in place. Then drop the tweeter in, twist it, and bam. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif You've just flush mounted your tweeters.