Previous accounts I've seen indicated that you'd want to use a shotgun. The idea is just to blow it apart until enough pieces fall down to meet your requirments.

Unfortunately those articles didn't provide a lot of detail about where to aim, or how much ammo you'd need for a decent harvest.

Harvesting Mistletoe

There may be other methods generically called "shooting" but if so I haven't seen details. Dynamite should work, but it skins up the tree.

John