its so very easy my dear..

all you need to do, is drain all the water contaminated by motor oil.. thats the only solution to that, coz there are no other way to remove that motor oil in that pool, coz water is very attractive to oil, it will stick and it will always go with it..

so sad to say, but you have to exert effort and time to change that pool as soon as possible.

I think there are absorbers you can get but….I would call a pool company & or an industrial cleaning company that could give you the proper instructions. I don’t think draining the pool is the answer without getting rid of as much oil as possible first.

You can either drain the pool, or you can overfill it the motor oil sits on top and over flow the pool till it is gone, but your best bet to make sure it is gone may be to overflow (it will help from most of the oil sticking to the sides making it easier to scrub) drain then scrub it..

You are going to have to drain the pool and get some industrial degreaser to wash it down and rinse well.