you need a spoke wrench, for a mountain bike wheel. bikeshop"£ 6 + turn the bike upside down , spin the wheel around till it rubs and stops at the brake pad" put the spoke key" over the nippel on the nearest spoke to were it is rubbing, just turn the spoke key anticlock , to open the spoke just a very little at a time,till the rubbing is gone , and the wheel is pulled away from the pads, and turn the next spoke to it clockwise, just a very little at a time, it will just be 3 spokes around were its rubbing that you have to work on , just a little turn at a time, and you will see the rim moveing in or out as you need it,
mick, August 2008