Oil stains are usually unexpected and can cause major anxiety. Making sure you get right on top of this is the most important part. First start by applying something to soak up the stain like a absorbent powder for oil stains (there are many different brands out there) the next step and calling a power washing company like power wash unlimited who has the right equipment to handle this mess. The key is to have the right chemical and to also have hot water that is soooo important in the process. But you have to always keep in mind that you might not be able to remove the stains 100% it all depends on the surface it has stained. Expecting to get 100% of the oil off is just setting yourself up for failure no one can promise that result. It is all dependent on how porous the pavers/concrete is.