Its got internal drum hanbrake so if you take the rear wheels off there will be a grommet in the drum, take out the grommet, shine a torch in the hole and turn the disc until you see the adjuster. Adjust the shoes out until the disc wont turn and then back it off a bit until the disc turns.
There is also a cable adjuster on the handbrake lever, from memory you have to remove the surround to get to it.