Break lights frozen to the socket

You can use a hair dryer to warm it up.
Use some needle nose pliers to get the bulb base out. But be careful of broken glass.

If you don't see a connector to unplug, then you're stuck working on it where it's at.
Or cut the wires and then splice them back together later.
But I don't recommend that.

You won't need to disconnect the battery, just make sure your lights are off.