Fix leak... Wash tray and re-install. Wait until you hit a massive chunk of ice in the winter before you replace.... trust me.
Leak is fixed. cleaned the plastic, but material has seen better days. Tried to soak up oil with rags, but still pretty wet. I am assuming the cloth-like material is there to absorb heat of engine and thus avoid melting the plastic tray.
Maybe get some degreaser. Zep brand is a pretty good one. But some hot water with Dawn dish soap should work well. Not Palmolive, not WalMart brand "Dawn"...but the real deal Dawn dish soap.
^^^^this^^^^ Buy a bottle for original Dawn dish soap, and a soft scrub brush. Douse the material with Dawn and water and gently scrub. Rinse thoroughly and let dry. You should be ok after that.