I bought one a few months back from the same seller and it does come with tools. You get the torx screwdriver, and anohter plastic "wedge" tool to help you push apart the faceplate once it's unscrewed (to prevent prying on the thing) There is a connector on the battery, no need to switch for polarity and there should be a little video showing you exactly how to do it.
Once you do the first one you'll be fine, i was nervous due to how much pressure i had to put on the connectors when pulling the original battery out, but it turned out fine. good luck.