[Chipper]

Inject early (search Chris Lilly's), rub just before putting on pit. Keep temp around 225-250 Wrap in foil at 165 with a little beef stock, then pull at 195. Rest for an hour or two in a cooler. Slice across the grain.
Depending on the size of the brisket, it could take 12 hours, so be patient and good luck.
This is a simple way to do it, I'm sure there are several other ways to get a fine product.