You can either drill with a jig and insert a bolt to hold the pin in place, or pull the gear case cover and tab the hole the pin can fall out of.
Having pulled the cover, I'd rather do that again; it didn't take incredibly long, and confirmed for me that I have the new-and-improved case that the pin can't fall out of (some 24-valves have it, some don't).
If you jig it, you can't see inside to figure out what's going on - the pin might be almost out, it could have fallen out and not gotten munched by the gears, etc... .
To pull the cover, you need to remove the fan, serpentine belt, fan shroud, coolant and windshield washer tanks, crank balancer, idler pulley, and about 25 bolts. You'll need a tab (search for "KDP tab," I think PDR and BD both sell kits), new crank seal and installer, and a gasket for the cover.
I got all my stuff through PDR, and I think it was about $90 shipped. All in all, the project took about six hours, but I was cleaning as I went and taking my sweet time.
I'm sure others will chime in if I missed anything.