I have an old 2 valve shower faucet from the 60s/70s. I removed the handle and was going to just replace the stem and seat but its not like the others I've seen online. If i'm correct the first nut is the packing nut but behind that is round and can't use a stem socket. How would I go about fixing this? Sorry for the newbie question just not sure what I should do and everything I find online says to remove the stem with a socket but I can't.