Replacing Gaskets on 90 degree oil filter adapter

Take off the filter first and most of the oil will come out. Some more will come form this being removed.

Don't use any sealer.

Everything is machined cast iron so it will be flat, and it is tough material. You can use a real razor blade with no problems. Problems arise quickly from those gasket remover abrasive wheels on a power tool.

Use a box wrench it might work better.