There are frequent minivans from Ivano-Frankivsk to Yaremcha. They leave from Ivano-Frankivsk train station and it takes only 1 or 2 hours to reach Yaremcha. Don't believe taxi drivers telling you there are no minivans (marshrutkas) to Yaremche or they are long or very expensive (taxi is much more expensive anyway). But ask local passengers on the minivan to tell when you will be in Yaremcha - we almost missed our stop. You can go there also by few daily buses, but minivans are faster and you will have a seat for sure.
Yaremcha Local Customs
This is a small town and people here are strongly religious. They greet each other by "Slava Yisusu!" - "Jesus is great!". They may greet this way even stranger like you. So, it is polite to answer the same way: "Slava Yisusu!". And this is totally Ukrainian speaking place. If you hear someone talking Russian, you know for sure they are tourists/travellers. So, for those of you who are able to speak Russian my advice is to learn some Ukrainian words or phrases. If you will use them in your Russian speach, locals will be pleased.