You don't use sealant for parts put together with O-rings. I didn't use sealant when I did the job. Be sure to lube the O-ring before use.
Recommend replacing the block to oil-filter adapter gasket at the same time. Not a very expensive gasket and makes sense after going through the work of draining oil/coolant.
Just took oil filter off but can't get to the bolts does the piece with the coolant hose come off, looks like a Allen wrench in the center where the oil filter goes on
Ok thanks, didn't have the correct wrench for that so I put it back together now I don't see an oil leak, put cardboard under the car overnight, with no drips.