You don't even need to take the Wheel off
It's been a while since I had my Sky, but It was super easy.
Open the hood
Turn the steering all the way so you get as much clearance in the wheel well as possible
and then you remove 5-8 bolts from the fender liner [I believe they are 5/8 but if not, everything else is 10mm

]
Disconnect the battery terminals and remove battery clamp
Slide it out of the wheel well
Slide new battery in
Attach battery clamp
attach wires to terminal.
I bet there is a video on one of these forums or Youtube that shows someone doing it.