One of my best wines is chokecherry! Check out my recipe to see how I did it. I have 5 gallons in secondary now, and I'll be making another 20 gallons or so this winter with frozen berries.
Even when they thaw, they are kind of hard to smash. I ended up getting a strainer type set up, with a wooden "smoosher" to smash the berries without breaking the pit. Then I put the fruit in a big mesh bag, so it could ferment but not be too much of a mess to remove.