On a good year, you can approach from the east, which would be a big day, but also a big, continuous descent. I have heard, but never confirmed, that it is possible to do it from the north. I think you have to time it just right – when the road is melted out, but the snow still hits the road. From what I can tell, this would be a world-class descent.
Llaima doesn't have a 'town' to call it's own. Temuco is a city. It's a cool, small, Chilean city, but it doesn't feel like a mountain town for sure. Most people ski Llaima from Pucón, which makes for a long day. You can also do it from the Lonquimay area, so sometimes it gets done while connecting those two destinations.
If you only have a week in Chile, Llaima probably won't make the list. But if you're there for two, you should put it on. It's a little bit of a hassle, but there's no one there and the terrain is stunning.