I have some oil drop stains and ALOT of water/rust stains on my white concrete driveway... its baked in their.... what can i use to get it out?

 

I used my 2400psi pressure washer to get out all of the oil stains my roomates ford left on our driveway. It worked really good (The pressure washer, not the ford) that is if you have access to a pressure washer

 

I used a pressure washer too, but I don;t even have a good one. It's like 1300psi and cost about $80US. I let the concrete soak a little with some simple green degreaser first.