Not sure if the arms and balljoints are the same as the pulsar
But when i had mine done on the pulsar, my friendly mot station pressed them out and pressed the new ones in for £15
Some of the spurious ones for the pulsar are under sized and people put 3 spot welds on the edge as someone else said
If they are the same as the pulsar?? You have to take the wheel off, undo the nut on the balljoint, split the joint, undo the arm and knock the retaining pin out, then the whole arm should drop out with a little bit of wigling