On my A7 I just found 2 bolts with the same thread as the tapped ones in the pinion and gradually tightened them up and they pushed the pinion off no bother, but I would not put too much pressure on as you could damage the crankcase looking at the general state of things you maybe better off making a puller as the previous post has indicated a bit of substantial flat bar with 3 holes in, the centre one drilled and tapped, the other 2 with clearance holes to suit tapped holes in the pinion.