gingerpubes

Just stand in front of it so it can't hit you(it may get the odd shot or blast at you) and use your burst cannon while aiming at the arms, it would be addvised to take out the right one first(the missile launcher)as it can cause some serious damage. If you are low on ammo there should be some lying around the back of the rubbish when you start the fight. It took me three goes.