The final fight against Jackenstein can be a bit tricky. Before you start you should have a Bee Shield and a good corrosive weapon (Conference Call works nicely). There are four parts to this battle. All very similar to the previous.
As soon as you jump down, unload on the electric power cells on it's back taking out 1/4 of his health. As soon as you take out one of them he will jump up and be protected by a shield. When this happens, you will need to take out a handful of Hyperion robots before he jumps back down. Unload on his second power cell when he does taking out another 1/4. He will jump back up to his previous spot and you will need to take care of more Hyperion robots. As soon as he jumps down again, use your most powerful weapon and unload in his chest/head region. His health will get bumped down from 50% to 25% then he'll die. Here is a basic video guide explaining what to do.
This one was definetely shorter compared to the other 2 storyline wise and probably sidequest wise to w/ the expection of finding rare animals. I enjoyed it, but was disappointed w/ the final boss in this DLC compared to the other 2, especially the pirate booty one. At least the pirate booty final boss was pretty tough.