By postal mail.
And there is no SASE enclosed.
This plan strikes me as coming dangerously close to the "unrealistic" line, given how hard it is to get people to put anything in the mail these days. (I know too many people who find the whole idea of sending postal mail quaint, since they are doing all their bill-paying online.) I still think Kingdom made a very poor choice in arrogating the election process to itself, but sobeit -- there's not a lot we can do about it.
So: if you are a paid member, *please* be sure to fill out and return your ballot, even if you look at the slates and have the entirely reasonable reaction of, "I don't much care -- they'd all do a good job". It looks like we need a serious get-out-the-vote effort if we're to avoid things getting weird and unfortunate. Spread the word...