Use a multi splined (not a 50p hex) 19mm socket on the bolt in the centre of the crank pulley, not the 4 or so allen key bolts that hold the pas/alt pulley to it. If ure under the front drivers side arch it turns clockwise, don't go anticlockwise cos if u do manage to slacken the bolt off/break the seal on the bolt it may loosen and kill the crank keyway, then the pulley moves, and dependin on how bad it goes u could kill valves/pistons. If I go slightly past the tdc mark, rather than go back on it,i go all the way round again to not risk loosenin it