Hard. Apartments are no good places for animals who depend on wallows for their wellbeing.

And keep in mind that they grow. Having a 150-250kg animal in your living room is no fun.

And they produce rather gross smelling shit and piss. Which might not make you friends with your neighbors.

Pig owner here. Keeping a pig in an apartment is going to be a little rough. You’d have to get them used to letting you put a harness on and walk them like a dog. I own my home, so I put in a huge dog door, worked great.

Probably the biggest problem is their intelligence and destructiveness. You’d have a huge job keeping a pig from getting bored when you’re gone. Maybe they can be crate trained? Mine figured out 3 different ways to get into the beer, even defeating a baby lock, and got hammered. He does love him some beer.

Hooves were a huge pain when my pig lived inside. They never got a chance to wear normally and I played hell getting him back and forth to the only vet in the area that would trim him. Even the local farrier had never done a pig. All that hassle, and I live on the edge of town in a redneck suburb. I seriously doubt you’re going to find a large animal vet in the city. You could probably work out the hoof thing with a rasp and 3 or 4 beers (for the pig, but you’ll both need that to get through the ordeal).

If it’s a male, you’ll probably want to trim his tusks once or twice a year. I got that done on the nail salon trips.

So, you’d have to get the pig used to a harness and car rides, find a vet or farrier for his hooves, and crate train him.

Oh, one other small thing. Once or twice a year, depending on the animal, pigs “blow coat”. This is not anything like shedding. ALL OF THEIR HAIR FALLS OUT AT ONCE. So there’s that to consider. :)