I tried this beer once. I think a close copy could be made by taking the liquid from canned cherries and mixing it 50/50 with cheap vodka. *shudder*
On a more helpful note, I'd follow the clues that the OP found. Find a belgian brown recipe to use as your base and experiment with it.
Perhaps some cherry juice in the primary as the ferment begins to wind down, then transfer to secondary on sour cherries. Not sure if I'd go 6 months on the cherries, but judging from the taste of the beer it wouldn't surprise me.