You may not want to hear this, but i cut mine out with an angle grinder, but i had another arm i was going to fit. You can drill the ends out and then remove the arm then get an engineering firm to press the spindle out (mine took 100 tonne press to get it moving) in the other arm, hacksaw the old bushes out to split them or use a gouging chisel.
But what do you put back, well it depends what you want to spend, i had a bronze bush conversion done on mine with grease nipples to keep it lubed up, cost about £100 - £150 but i feel it was well worth it, as i can now take the arm out in about 15 mins.
