How to open up the seat?

The first thing you want to do is grab the key, and then put it in the ignition. Don’t push the key in, just turn it left, and then the seat will open up. Even if there is just the slightest bit of pressure, the key is not going to turn in, you just want to turn it left so you can open up that seat.

How to unlock the battery?

To unlock batteries, open the seat as they were getting to the circuit breaker, turning the key left WITHOUT pushing the key in. Once that has been done, there will be some bolts that hold the black box onto the frame. Once those have been removed the batteries will be exposed.