I sprayed oil pan first first with an aerosol engine degreaser & wiped with paper towels after letting it sit 5 to 10 minutes. Once the thick oil sludge was off I used a cheaper orange spray bottle degreaser rubbed around with hand let sit 10 min & washed off with hose. Then I scraped it per video & washed again. Then I could see some areas with a little gasket material left. So I scraped those with puddy knife. Be careful to keep it flat or you will scratch the surface. Finally I sanded over it all with a very fine sand paper. Around 300 grit.