Here's the youtube video I followed to re-wire for 240V or 120V usage.
https://youtu.be/D2-_pfCtPu4
Assuming your charger looks the same on the inside as this one (clippercreek board), then it's capable of 240V charging @ 12amps. Note that you'll need a 240V outlet that includes both hots, neutral, and ground. That's four prongs total, which is unusual to find. I happened to have an L14-30 outlet in my garage. An L14-20 would also work, and is what the video shows.
If you don't know what you're doing, this could obviously be dangerous. So, proceed at your own risk!