I changed my plugs a couple of weeks ago. First time on this bike (2006 RSTD). Have done it a few times on my previous Roadstar. The Roadstar is easier/quicker (and needed it more often).
I did go to the Iridium Plugs (Carquest for about $8 each). Gap 32-35.
I did have to remove the tank and seat.
I ended up having to use the tool kit plug wrench because my plug socket would not get deep enough to turn the plug. I did remove the front engine mounts (one at a time for good luck). Use a can of compressed air to blow out any grit or pebbles before you pull the old plug.
Two problems I had:
A) the chrome (plastic) piece around the gas cap has 4 bolts. The nuts can free spin in their rubber grommets. One was a real fight.
B) I was so proud when I looked in my bolt bucket and saw no spare parts left over,,,, until I looked where the tank had sat and saw this big rubber thing (looked like a starwars mock up). What the hell is that??? It was a "rubber baby buggy bumper" thing that keeps the tank from rattling. It stuck to the tank when I pulled it, fell off, and I didn't see it when I picked up the tank to put it back on. So,,, I had to take it all apart again. So, I kind of did this twice!
By the way, my old plugs looked fine, 23K. I haven't noticed any gain by going to the Iridium plugs. SO, being a RSTD, it still runs great!!!!
Mike G in SC