I have a 1987 vet that started leaking oil above the oil filter. I’m fairly certain it is a bad seal above the oil filter adapter and I found a replacement on line but am perplexed on how to remove the adapter. See photo attached. I was told that the nut unscrews but I can’t find a socket to fit and I’m wondering if it isn’t a nut but a pressed part of the adapter and whether the entire adapter unscrews after unhooking the oil lines. All input welcome.