how do i eat ass?

i’ve been casually hooking up with this guy and he’s mentioned a few times that he wants me to eat his ass. im a bi woman so i’ve eaten out other women but never a mans ass. i have no idea what to do if i decide to go through with it. i also have long acrylic nails so im not like really able to do much. pls give me any tips if you can bc i want to make it pleasurable for both of us.
and i have asked him what he wants specifically but he wasn’t really informative so that’s why im here