Well at your request a how to on how to install the Infinity kappa tweeters in the stock location, and i still kept it clean and look like factory. I have owned these speakers now for about a year, but because of work and deployments i got lazy and never installed the tweeters until now after reading your post. So this is what i did:

First i removed the factory tweeter and mount from the door, i just cut the wires near the oem tweeter cause i am not going to be using it but left original wiring in place anyway. So once i had the tweeter assy. out i came inside and started looking it over trying to decide how i was going to do it. I wanted to keep it as clean as possible.

Next removed the screw that holds the tweeter in place and removed the speaker. Now not everyone is going to want to do what i did next but oh well. So pretty much i broke out the dremel tool with adjustable speed and procided to pretty much cut out the original tweeter from the shell/grill assy. that holds the speaker in place. I used this little raotory bit with the dremel and cut around the speaker itself until the magnet part came out. Then cut away the rest of the plastic speaker shell inside the tweeter holder thingy and pretty much all i had left was the shell plastic cover with the grill. I used a little sanding drum and cleaned up the loose plastic so that the infinity speaker fits pretty much inside prefectly. Now with the piece that mounts in the door theres a little nipple thing where the tweeter goes into and i removed that so the tweeter and shell assy fits perfect like OEM. I left the original silver tweeter grill on the infinity tweeter also.

So once everything is fit perfectly you can use a epoxy 2 part glue to hold the tweeter in place in the original oem tweeter grill and let dry. Then put your new infinity tweeter with the oem shell and mount inside the piece that goes in the door and epoxy in place also. Once everything is dry you can check fitment and then wire your tweeter and woofer to the crossover and to your amp or to your stereo. My alpine puts out 60w RMS per channel so it should be good enough and since i dont have amp right now to run it i am going to wire it in that way from now. Heres some pics in order of how i explained it.

This might not be the greatest how to ever posted but think most should get the idea. Once everything is put together it pretty much looks OEM but if you look closely you can see the little Infinity sign on the tweeter.