Nice investment! Loved these on my previous jku; nice to not rattle the teeth out of your jaw every time you come down off a rock or mound. Which reminds me that I need to get a set of these ordered up for the new one.
When I did mine I also could not find a spanner wrench to use locally; as JKRicky said, just a flathead and a few taps of a hammer does the trick. I also put some electrical tape over the tip to help keep from marring/gouging up the nut... which in hindsight was kind of a silly concern considering all the trail tattoos that jeep had, lol.